Negative pressure wound therapy apparatus and methods

ABSTRACT

Systems and methods for controlling a pump system for use in negative pressure wound therapy are described herein. In some embodiments, a method for controlling a pump system includes applying a drive signal to a pump assembly of the pump system, the drive signal alternating between a positive amplitude and a negative amplitude and the drive signal having an offset, and sampling a pressure within a fluid flow path configured to connect the pump system to a wound dressing configured to be placed over a wound during one or more time intervals. Each of the one or more time intervals can occur when the drive signal is approximately at an amplitude equal to one or more sampling amplitudes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/095,721, filed Dec. 22, 2014, titled “NEGATIVE PRESSURE WOUND THERAPYAPPARATUS AND METHODS,” the disclosure of which is hereby incorporatedby reference in its entirety herein.

INCORPORATION BY REFERENCE

Further components, features, and details of pump assemblies, wounddressings, wound treatment apparatuses and kits, and negative pressurewound treatment methods that may be used with any of the embodimentsdisclosed in this application are found in the following applicationsand/or publications, which are hereby incorporated by reference in theirentireties herein.

U.S. patent application Ser. No. 14/715,527, filed May 18, 2015, titled“FLUIDIC CONNECTOR FOR NEGATIVE PRESSURE WOUND THERAPY.”

U.S. patent application Ser. No. 14/418,908 (U.S. Patent Publication No.2015/0190286), filed Jan. 30, 2015, titled “WOUND DRESSING AND METHOD OFTREATMENT.”

U.S. patent application Ser. No. 14/403,036 (U.S. Patent Publication No.2015/0141941), filed Nov. 21, 2014, titled “APPARATUSES AND METHODS FORNEGATIVE PRESSURE WOUND THERAPY.”

PCT International Application No. PCT/IB2013/001513 (InternationalPublication No. WO/2013/171585), filed May 15, 2013, titled “NEGATIVEPRESSURE WOUND THERAPY APPARATUS.”

PCT International Application No. PCT/IB2013/000847 (InternationalPublication No. WO/2013/136181), filed Mar. 12, 2013, titled “REDUCEDPRESSURE APPARATUS AND METHODS.”

U.S. patent application Ser. No. 13/092,042 (U.S. Patent Publication No.2011/0282309), filed Apr. 21, 2011, titled “WOUND DRESSING AND METHOD OFUSE.”

Each and all of the foregoing patent applications are herebyincorporated by reference in their entireties and made part of thisdisclosure.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

Embodiments or arrangements disclosed herein relate to methods andapparatuses for dressing and treating a wound with topical negativepressure (TNP) therapy. For example but without limitation, anyembodiments disclosed herein relate to treating a wound with reducedpressure provided from a pump kit. Although not required, anyembodiments of the pump kit can be sterile. As another non-limitingexample, any embodiments disclosed herein relate to apparatuses andmethods for controlling the operation of a TNP system.

Description of the Related Art

Many different types of wound dressings are known for aiding in thehealing process of a human or animal. These different types of wounddressings include many different types of materials and layers, forexample, pads such as gauze pads and/or foam pads. Topical negativepressure (“TNP”) therapy, sometimes referred to as vacuum assistedclosure, negative pressure wound therapy, or reduced pressure woundtherapy, is widely recognized as a beneficial mechanism for improvingthe healing rate of a wound. Such therapy is applicable to a broad rangeof wounds such as incisional wounds, open wounds and abdominal wounds orthe like.

TNP therapy assists in the closure and healing of wounds by reducingtissue oedema; encouraging blood flow; stimulating the formation ofgranulation tissue; removing excess exudates, and may reduce bacterialload and thus reduce the potential for infection of the wound.Furthermore, TNP therapy permits less outside disturbance of the woundand promotes more rapid healing.

SUMMARY OF SOME EMBODIMENTS

Embodiments of the present disclosure relate to apparatuses and methodsfor wound treatment. Some of the wound treatment apparatuses describedherein comprise a pump system for providing negative pressure to a woundsite. Wound treatment apparatuses may also comprise wound dressings thatmay be used in combination with the pump assemblies described herein,and connectors for connecting the wound dressings to the pumpassemblies.

In some embodiments, an apparatus for use in negative pressure woundtherapy comprises a pump assembly, comprising an electrically conductivecoil, a magnet, a diaphragm, and a dampener. The coil can be directly orindirectly coupled with the diaphragm and can be configured to move atleast a portion of the diaphragm to pump a fluid through the pumpassembly in response to a drive signal applied to the coil.

The apparatus, which may be or include a pump apparatus, may be arrangedsuch that the pump assembly includes an electrically conductive upperpole, an electrically conductive lower pole, and one or more valves,wherein the magnet is positioned between at least a portion of the upperpole and the lower pole, and wherein the coil is positioned between atleast a portion of the upper pole and the lower pole. The pump apparatusmay be arranged such that the pump housing includes a chamber withinwhich the dampener can be positioned. The pump apparatus may be arrangedsuch that the dampener is retained within the chamber via aninterference fit. The pump apparatus may be arranged such that the pumphousing includes an exhaust channel designed to communicate fluid flowout of the pump assembly, the chamber being in communication with theexhaust channel. The pump apparatus may be arranged such that thechamber includes an opening. The pump apparatus may be arranged suchthat the chamber includes one or more ribs, the ribs spacing thedampener from the opening. The pump apparatus may be arranged such thatthe opening is positioned at an end of the exhaust channel.

The pump apparatus may be arranged such that it includes a manifoldpositioned between the pump assembly and a wound dressing. The pumpapparatus may be arranged such that it includes a second dampener withinthe manifold. The pump apparatus may be arranged such that it includes acontrol board. The pump apparatus may be arranged such that it includesan electrical conduit for connecting the control board to theelectrically conductive coil. The pump apparatus may be arranged suchthat it includes a wound dressing designed to sealingly surround awound. The pump apparatus may be arranged such that it includes a springmember wherein a periphery of the spring member is supported within thepump assembly so as to be in a fixed position relative to the diaphragmand a middle portion of the spring member is designed to deflectrelative to the periphery of the spring member when a middle portion ofthe diaphragm axially deflects.

In some embodiments disclosed herein, the pump system can optionallyform part of a wound treatment apparatus that also includes a wounddressing. In some embodiments, the pump system and/or a wound dressingcan optionally have one or more sensors therein. For example, in someembodiments disclosed herein, the pump system and/or dressing can have apressure monitor configured to monitor the pressure within the pumphousing, dressing, or conduit or chambers within the pump system orbetween the pump system and the dressing, or in any combination of such.Additionally, some pump embodiments disclosed herein can use orifices orother features or components to control a flow or rate of flow of fluidthrough the pump system.

Some embodiments disclosed herein may also relate to a negative pressuretherapy kit for reduced pressure wound therapy. The negative pressuretherapy kit in some embodiments may include a pump system having anouter housing, a pump assembly supported within the housing, and acontroller supported within or by the outer housing. In someembodiments, at least one switch or button may be supported by the outerhousing. The at least one switch or button can be in communication withthe controller and can be accessible to a user so as to permit a user tocontrol one or more modes of operation of the pump system.

In some embodiments disclosed herein, though not required, a negativepressure therapy system can comprise a dressing configured to form asubstantially fluid tight seal over a wound and a conduit coupleablewith the dressing and the pump system and configured to provide asubstantially or completely enclosed fluid flow pathway from the pumpsystem to the dressing.

In some embodiments, a method for controlling a pump system can includecalculating at least one of an amplitude and an offset for a drivesignal based at least in part on previously calculated parameters and anegative pressure setting, generating the drive signal with the at leastone calculated amplitude and offset, and applying the drive signal tothe pump system. In some embodiments, the method can be performed undercontrol of a controller of the pump system.

In some embodiments, the previously calculated parameters can include aplurality of calibrated amplitudes at a plurality of negative pressuresettings. In some embodiments, the previously calculated parameters caninclude a plurality of calibrated offsets at a plurality of negativepressure settings. In some embodiments, the previously calculatedparameters can include at least 3 parameters. In some embodiments, thepreviously calculated parameters can be specific to the pump system. Insome embodiments, calculating the at least one of the amplitude and theoffset for a drive signal can include calculating both the amplitude andthe offset for the drive signal. In some embodiments, calculating the atleast one of the amplitude and the offset for the drive signal caninclude interpolating between at least two previously calculatedamplitudes or offsets. In some embodiments, the interpolation can be alinear interpolation. In some embodiments, the pump system can include avoice coil actuator connected to a diaphragm. In some embodiments, thepump system can include a spring which can affect a resonant frequencyof the pump system.

In some embodiments, the method can include applying a start up signalwhen the pump system has been activated after a period of inactivity,the start up signal having at least one of an amplitude and an offsetdifferent from at least one of the amplitude and the offset of the drivesignal. In some embodiments, the method can include calculating at leastone of an amplitude and an offset for the start up signal based at leastin part on previously calculated parameters and a negative pressuresetting less than the negative pressure setting for calculating thedrive signal. In some embodiments, the method can include generating thestart up signal with the at least one calculated amplitude and offset.

In some embodiments, a pump system for negative pressure wound therapycan include a pump assembly, having an actuator and a diaphragm, and acontroller which can control operation of the pump system. In someembodiments, the controller can calculate at least one of an amplitudeand an offset for a drive signal based at least in part on previouslycalculated parameters and a negative pressure setting, generate thedrive signal with the at least one calculated amplitude and offset andapply the drive signal to the pump system.

In some embodiments, the previously calculated parameters can include aplurality of calibrated amplitudes at a plurality of negative pressuresettings. In some embodiments, the previously calculated parameters caninclude a plurality of calibrated offsets at a plurality of negativepressure settings.

In some embodiments, the controller can calculate both the amplitude andthe offset for the drive signal. In some embodiments, the controller caninterpolate between at least two previously calculated amplitudes oroffsets. In some embodiments, the controller can linearly interpolatebetween at least two previously calculated amplitudes or offsets. Insome embodiments, the previously calculated parameters can include atleast 3 parameters. In some embodiments, the previously calculatedparameters can be specific to the pump system. In some embodiments, theactuator can include a voice coil actuator connected to the diaphragm.In some embodiments, the pump assembly can include a spring which canaffect a resonant frequency of the pump assembly.

In some embodiments, the controller can apply a start up signal when thepump system has been activated after a period of inactivity, the startup signal having at least one of an amplitude and an offset differentfrom at least one of the amplitude and the offset of the drive signal.In some embodiments, the controller can calculate at least one of anamplitude and an offset for the start up signal based at least in parton previously calculated parameters and a negative pressure setting lessthan the negative pressure setting for calculating the drive signal andgenerate the start up signal with the at least one calculated amplitudeand offset.

In some embodiments, a method for calibrating a pump system for negativepressure wound therapy can include generating a drive signal, actuatingthe pump system with the drive signal, measuring movement of a componentof the pump system, calculating a first dimension based on the measuredmovement of the component and determining whether a convergencecondition has been satisfied, wherein the convergence conditioncomprises a first condition that the first dimension be within a firsttolerance of a first target value. In some embodiments, the method canbe performed under control of a controller of the pump system.

In some embodiments, the method can include calculating a seconddimension based on the measured movement of the component. In someembodiments, the convergence condition can include a second conditionthat the second dimension be within a second tolerance of a secondtarget value. In some embodiments, the convergence condition can includea third condition that the first condition and the second condition aresatisfied substantially simultaneously. In some embodiments, in responseto determining that the convergence, the method can include storing aset of parameters associated with the drive signal condition is met. Insome embodiments, in response to determining that the convergencecondition is not satisfied, the method can include adjusting one or moreparameters of the drive signal based at least in part on the measuredmovement of the component, generating an adjusted drive signal,actuating the pump system with the adjusted drive signal, measuring themovement of the component of the pump assembly, and determining whetherthe convergence condition has been satisfied.

In some embodiments, generating the drive signal includes selecting anamplitude of the drive signal. In some embodiments, generating the drivesignal includes selecting an offset of the drive signal. In someembodiments, at least one of the first and second dimensions includes atravel of the component. In some embodiments, at least one of the firstand second dimensions includes an average position of the component. Insome embodiments, the component includes a piston connected to adiaphragm.

In some embodiments, a calibration system for calibrating a pump systemfor negative pressure wound therapy can include a sensor and acontroller which can control operation of the calibration system. Insome embodiments, the controller can generate a drive signal, actuatethe pump system with the drive signal, measure movement of a componentof the pump system with the sensor, and calculate a first dimensionbased on the measured movement of the component, and determine whether aconvergence condition has been satisfied, wherein the convergencecondition can include a first condition that the first dimension bewithin a first tolerance of a first target value.

In some embodiments, the controller can calculate a second dimensionbased on the measured movement of the component. In some embodiments,the convergence condition can include a second condition that the seconddimension be within a second tolerance of a second target value. In someembodiments, the convergence condition can include a third conditionthat the first condition and the second condition are satisfiedsubstantially simultaneously. In some embodiments, upon determining thatthe convergence condition is met, the controller can store a set ofparameters associated with the drive signal. In some embodiments, upondetermining that the convergence condition is not satisfied, thecontroller can adjust one or more parameters of the drive signal basedat least in part on the measured movement of the component, generate anadjusted drive signal, actuate the pump system with the adjusted drivesignal, measure the movement of the component of the pump assembly withthe sensor, and determine whether the convergence condition has beensatisfied. In some embodiments, the controller can select an amplitudeof the drive signal when generating the drive signal. In someembodiments, the controller can select an offset of the drive signalwhen generating the drive signal. In some embodiments, at least one ofthe first and second dimensions can include a travel of the component.In some embodiments, at least one of the first and second dimensions caninclude an average position of the component. In some embodiments, thecomponent can include a piston connected to a diaphragm.

In some embodiments, a method for controlling a pump system for negativepressure wound therapy can include providing negative pressure, via aflow path, to a wound dressing positioned over a wound, the flow pathfluidically connecting the pump system to the wound dressing, measuringa first pressure value in the flow path at a first time, measuring asecond pressure value in the flow path at a second time, calculating afirst rate of pressure change using the first and second pressure valuesand in response to determining that the calculated first rate ofpressure change satisfies a threshold rate, providing an indication thatthe wound dressing is full. In some embodiments, the method can beperformed under control of a controller of the pump system.

In some embodiments, the method can include measuring a third pressurevalue in the flow path at a third time, measuring a fourth pressurevalue within the flow path at a fourth time, calculating a second rateof pressure change using the third and fourth pressure values, andproviding the indication that the wound dressing is full in response todetermining that the calculated first and second rates of pressurechange satisfy the threshold rate. In some embodiments, the pressure inthe fluid flow path is between a maximum pressure and a minimumpressure. In some embodiments, the method can include determiningwhether the second pressure value is less than a minimum pressure.

In some embodiments, a pump system for negative pressure wound therapycan include a pump assembly to provide a negative pressure, via a flowpath, to a wound dressing positioned over a wound, the flow pathfluidically connecting the pump system to the wound dressing, a sensorwhich can measure a pressure in the flow path, and a controller whichcan control operation of the pump system. In some embodiments, thecontroller can measure a first pressure value in the flow path at afirst time, measure a second pressure value in the flow path at a secondtime, calculate a first rate of pressure change using the first andsecond pressure values and provide an indication that the wound dressingis full in response to determining that the calculated first rate ofpressure change satisfies a threshold rate.

In some embodiments, the controller can measure a third pressure valuein the flow path at a third time, measure a fourth pressure value withinthe flow path at a fourth time, calculate a second rate of pressurechange using the third and fourth pressure values and provide theindication that the wound dressing is full in response to determiningthat the calculated first and second rates of pressure change satisfythe threshold rate. In some embodiments, the pressure in the fluid flowpath is between a maximum pressure and a minimum pressure. In someembodiments, the controller can determine whether the second pressurevalue is less than a minimum pressure.

In some embodiments, a method for controlling a pump system for negativepressure wound therapy can include applying a drive signal to a pumpassembly of the pump system, the drive signal alternating between apositive amplitude and a negative amplitude and the drive signal havingan offset and sampling a pressure within a fluid flow path connectingthe pump system to a wound dressing placed over a wound during one ormore time intervals, wherein each of the one or more time intervalsoccurs when the drive signal is approximately at an amplitude that issubstantially at one or more sampling amplitudes. In some embodiments,the method can be performed under control of a controller of the pumpsystem.

In some embodiments, the sampling amplitude can include a local maximaof the amplitude. In some embodiments, the sampling amplitude caninclude a local minima of the amplitude. In some embodiments, thesampling amplitude can include a zero crossing of the amplitude. In someembodiments, the sampling amplitude can include an offset crossing ofthe amplitude. In some embodiments, the method can include, during eachof the one or more time intervals, sampling the pressure at least twice.In some embodiments, the method can include averaging the pressuresamples during each time interval.

In some embodiments, a pump system for negative pressure wound therapycan include a pump assembly, having an actuator and a diaphragm, and acontrolled which can control operation of the pump system. In someembodiments, the controller can apply a drive signal to the pumpassembly, the drive signal alternating between a positive amplitude anda negative amplitude and the drive signal having an offset and sample apressure within a fluid flow path connecting the pump assembly to awound dressing placed over a wound during one or more time intervals,wherein each of the one or more time intervals occurs when the drivesignal is approximately at an amplitude that is substantially at one ormore sampling amplitudes.

In some embodiments, the sampling amplitude can include a local maximaof the amplitude. In some embodiments, the sampling amplitude caninclude a local minima of the amplitude. In some embodiments, thesampling amplitude can include a zero crossing of the amplitude. In someembodiments, the sampling amplitude can include an offset crossing ofthe amplitude. In some embodiments, during each of the one or more timeintervals, the controller can sample the pressure at least twice. Insome embodiments, the controller can average the pressure samples duringeach time interval.

In various embodiments, a pump system configured for negative pressurewound therapy is described. The pump system can include a pump assemblyand a controller. The pump assembly can include an actuator and adiaphragm. The controller can be configured to control operation of thepump system. The controller can be configured to apply a drive signal tothe pump assembly, the drive signal alternating between a positiveamplitude and a negative amplitude and the drive signal having anoffset. The controller can be configured to sample a pressure within afluid flow path configured to connect the pump assembly to a wounddressing configured to be placed over a wound during one or more timeintervals, wherein each of the one or more time intervals occurs whenthe drive signal is approximately at an amplitude equal to one or moresampling amplitudes.

In various embodiments, a method for controlling a pump systemconfigured for negative pressure wound therapy is described. The methodcan include applying a drive signal to a pump assembly of the pumpsystem, the drive signal alternating between a positive amplitude and anegative amplitude and the drive signal having an offset. The method caninclude sampling a pressure within a fluid flow path configured toconnect the pump system to a wound dressing configured to be placed overa wound during one or more time intervals. Each of the one or more timeintervals can occur when the drive signal is approximately at anamplitude equal to one or more sampling amplitudes. The method can beperformed under control of a controller of the pump system.

Any of the features, components, or details of any of the arrangementsor embodiments disclosed in this application, including withoutlimitation any of the pump embodiments (for example, any of the voicecoil pump embodiments) and any of the negative pressure wound therapyembodiments disclosed below, are interchangeably combinable with anyother features, components, or details of any of the arrangements orembodiments disclosed herein to form new arrangements and embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described hereinafter,by way of example only, with reference to the accompanying drawings inwhich:

FIG. 1 is a front perspective view of an embodiment of a pump systemhaving an outer housing with an optional mounting component attachedthereto.

FIG. 2 is a front view of the pump system of FIG. 1.

FIG. 3 is a rear perspective view of the pump system of FIG. 1.

FIG. 4 is a rear view of the pump system of FIG. 1.

FIG. 5 is a top view of the pump system of FIG. 1.

FIG. 6 is a bottom view of the pump system of FIG. 1.

FIG. 7 is a right side view of the pump system of FIG. 1.

FIG. 8 is a left side view of the pump system of FIG. 1.

FIG. 9 is a rear view of the outer housing of FIG. 1, without theoptional mounting component.

FIG. 10 is a rear view of the outer housing of FIG. 9, with a coverremoved to expose cavity within the outer housing.

FIG. 11 is a front perspective view of the outer housing of FIG. 1, witha front portion of the outer housing removed to expose an embodiment ofa circuit board and pump assembly.

FIG. 12 is a rear perspective view of the outer housing of FIG. 1, witha rear portion of the outer housing removed to expose an embodiment of acircuit board and pump assembly.

FIG. 13 is a front perspective view of the outer housing of FIG. 1, witha front portion of the outer housing and the circuit board removed toexpose the pump assembly.

FIG. 14 is a front perspective view of an embodiment of a pump assemblyand an intake manifold.

FIG. 15 is a rear view of the pump assembly and intake manifold of FIG.14.

FIG. 16 is a front view of the pump assembly and intake manifold of FIG.14.

FIG. 17A is a cross sectional view of the intake manifold of FIG. 14.

FIG. 17B is a cross sectional view of the intake manifold with an outerhousing and a control board.

FIG. 18 is a cross sectional view of the pump assembly of FIG. 14.

FIGS. 19-20 are exploded views of the pump assembly of FIG. 14

FIG. 21 is a rear view of an embodiment of a pump housing

FIG. 22 is a front view of the pump housing of FIG. 21.

FIGS. 23-24 are perspective views of an embodiment of a valve.

FIG. 25 is a perspective view of an embodiment of a pump chamber body.

FIG. 26 is a front view of the pump chamber body of FIG. 25.

FIG. 27 is a rear view of the pump chamber body of FIG. 25.

FIGS. 28-29 are perspective view of an embodiment of a diaphragm.

FIG. 30 is a side view of the diaphragm of FIGS. 28-29.

FIG. 31 is a side, cross-sectional view of the diaphragm of FIGS. 28-29.

FIG. 32 is a perspective view of an embodiment of a spacer.

FIG. 33 is a side, cross-sectional view of the spacer of FIG. 32.

FIGS. 34-35 are perspective views of an embodiment of a support member.

FIG. 36 is a perspective view of an embodiment of a shaft.

FIG. 37 is a side view of the shaft of FIG. 36.

FIG. 38 is a perspective view of an embodiment of a spring.

FIGS. 39-40 are perspective views of an embodiment of a bushing.

FIG. 41 is a rear view of an embodiment of the pump housing of FIG. 21with a dampening element.

FIG. 42 is a side, cross-sectional view of the pump housing anddampening element of FIG. 41.

FIG. 43 is a perspective view of an embodiment of a detachable chamber.

FIG. 44 is a perspective view of another embodiment of a pump housing.

FIG. 45 is a perspective view of another embodiment of a pump housing.

FIG. 46 is a side, cross-sectional view of another embodiment of amanifold.

FIG. 47 is a perspective view of another embodiment of a pump housing.

FIG. 48 is a front view of the circuit board of FIG. 11.

FIG. 49 is a rear view of the circuit board of FIG. 11.

FIG. 50 is a perspective view of another embodiment of a support memberand coil.

FIG. 51 is a schematic, cross-sectional view of an embodiment of wiringfor the coil and support member of FIG. 50.

FIG. 52 is a schematic, cross-sectional view of another embodiment ofwiring for the coil and support member of FIG. 50.

FIG. 53 is a schematic, cross-sectional view of another embodiment ofwiring for the coil and support member of FIG. 50.

FIG. 54 is a schematic, cross-sectional view of another embodiment ofwiring for the coil and support member of FIG. 50.

FIG. 55 is a perspective view of an embodiment of a combined spring andelectrical conduit.

FIG. 56 is an embodiment of an arrangement of icons for a display.

FIG. 57A is a top view of an embodiment of a pump system attached to awound dressing.

FIG. 57B is a view of an embodiment of a pump system configured to beattached to a wound dressing.

FIG. 58 is a top view of an embodiment of a weld contour between a pumphousing and a pump chamber body.

FIG. 59 is a top view of an embodiment of a weld contour between a pumpchamber body and a bushing.

FIG. 60 is a schematic of an embodiment of a pump system.

FIG. 61 is a schematic of another embodiment of a pump system.

FIG. 62 is a schematic of another embodiment of a pump system.

FIG. 63 is a top level state diagram according to some embodiments.

FIG. 64 is an exemplary pressure versus time graph according to someembodiments.

FIG. 65 is an exemplary drive signal for a source of negative pressureaccording to some embodiments.

FIG. 66 is a schematic illustrating the generation of a drive signalaccording to some embodiments.

FIG. 67 is an embodiment of a calibration method for generatingparameters of a drive signal.

FIG. 68 is an exemplary travel versus iteration graph according to someembodiments.

FIG. 69 is an exemplary average position versus iteration graphaccording to some embodiments.

FIG. 70 is an embodiment of a method for determining a filter blockage.

FIG. 71 is an exemplary pressure versus time graph according to someembodiments.

FIG. 72 is another embodiment of a method for determining a filterblockage.

FIG. 73 is a front perspective view of the pump system of FIG. 1 withoutthe optional mounting component attached.

FIG. 74 is a front view of the pump system of FIG. 73.

FIG. 75 is a rear perspective view of the pump system of FIG. 73.

FIG. 76 is a rear view of the pump system of FIG. 73.

FIG. 77 is a top view of the pump system of FIG. 73.

FIG. 78 is a bottom view of the pump system of FIG. 73.

FIG. 79 is a right side view of the pump system of FIG. 73.

FIG. 80 is a left side view of the pump system of FIG. 73.

FIG. 81 is a front perspective view of a pump mounting component.

FIG. 82 is a front view of the pump mounting component of FIG. 81.

FIG. 83 is a rear perspective view of the pump mounting component ofFIG. 81.

FIG. 84 is a rear view of the pump mounting component of FIG. 81.

FIG. 85 is a top view of the pump mounting component of FIG. 81.

FIG. 86 is a bottom view of the pump mounting component of FIG. 81.

FIG. 87 is a right side view of the pump mounting component of FIG. 81.

FIG. 88 is a left side view of the pump mounting component of FIG. 81.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

Embodiments disclosed herein relate to apparatuses and methods oftreating a wound with reduced pressure, including pump and wounddressing components and apparatuses. The apparatuses and componentscomprising the wound overlay and packing materials, if any, aresometimes collectively referred to herein as dressings.

It will be appreciated that throughout this specification reference ismade to a wound. It is to be understood that the term wound is to bebroadly construed and encompasses open and closed wounds in which skinis torn, cut or punctured or where trauma causes a contusion, or anyother surficial or other conditions or imperfections on the skin of apatient or otherwise that benefit from reduced pressure treatment. Awound is thus broadly defined as any damaged region of tissue wherefluid may or may not be produced. Examples of such wounds include, butare not limited to, acute wounds, chronic wounds, surgical incisions andother incisions, subacute and dehisced wounds, traumatic wounds, flapsand skin grafts, lacerations, abrasions, contusions, burns, diabeticulcers, pressure ulcers, stoma, surgical wounds, trauma and venousulcers or the like. In some embodiments disclosed herein, the componentsof the TNP system described herein can be particularly suited forincisional wounds that exude a small amount of wound exudate.

It will be understood that embodiments of the present disclosure aregenerally applicable to use in topical negative pressure (“TNP”) therapysystems. Briefly, negative pressure wound therapy assists in the closureand healing of many forms of “hard to heal” wounds by reducing tissueoedema, encouraging blood flow and granular tissue formation, and/orremoving excess exudate and can reduce bacterial load (and thusinfection risk). In addition, the therapy allows for less disturbance ofa wound leading to more rapid healing. TNP therapy systems can alsoassist in the healing of surgically closed wounds by removing fluid andby helping to stabilize the tissue in the apposed position of closure. Afurther beneficial use of TNP therapy can be found in grafts and flapswhere removal of excess fluid is important and close proximity of thegraft to tissue is required in order to ensure tissue viability.

As is used herein, reduced or negative pressure levels, such as −X mmHg,represent pressure levels that are below standard atmospheric pressure,which corresponds to 760 mmHg (or 1 atm, 29.93 mmHg, 101.325 kPa, 14.696psi, etc.). Accordingly, a negative pressure value of −X mmHg reflectsabsolute pressure that is X mmHg below 760 mmHg or, in other words, anabsolute pressure of (760−X) mmHg. In addition, negative pressure thatis “less” or “smaller” than X mmHg corresponds to pressure that iscloser to atmospheric pressure (e.g., −40 mmHg is less than −60 mmHg).Negative pressure that is “more” or “greater” than −X mmHg correspondsto pressure that is further from atmospheric pressure (e.g., −80 mmHg ismore than −60 mmHg).

The operating negative pressure range for some embodiments of thepresent disclosure can be between approximately −20 mmHg andapproximately −200 mmHg, between approximately −50 mmHg andapproximately −150 mmHg, between approximately −70 mmHg and −90 mmHg,any subrange within these ranges, or any other range as desired. In someembodiments, an operating negative pressure range of up to −70 mmHg, upto −80 mmHg, up to −90 mmHg, up to −100 mmHg, up to −110 mmHg, or up toany other pressure as desired can be used. For example, in someembodiments, the pump system can maintain negative pressure woundtherapy at −80 mmHg (nominal)+/−20 mmHg to a wound dressing and/or to awound surface. Other details regarding the operation of the pump systemare set forth in U.S. Publication Nos. 2011/0282309, 2013/0110058 and2013/0331823 as well as International Patent Publication No.2013/171585, and all embodiments, configurations, details, andillustrations of these publications are hereby incorporated by referencein their entireties as if made part of this disclosure.

Any of the embodiments disclosed herein can include a pump and/or a pumpand dressing kit. However, the pump apparatuses and embodiments of thepresent disclosure are not limited to use with a dressing or for woundtherapy. Any of the pump embodiments disclosed herein can be usedindependently of the dressing components disclosed herein. Further, anyof the pump embodiments disclosed herein can be used, or can be adaptedfor use, for other purposes outside of negative pressure wound therapy.As such, any of the pump embodiments disclosed herein can be used, orcan be adapted for use, to move fluids (gaseous and/or liquid) in anysystem or application. Any of the embodiments disclosed herein can beused on an exuding wound. For example, in some embodiments, the pumpand/or kit can be used on wounds where the level of exudate is low(e.g., 0.6 g (nominal) of liquid exudate/cm² of wound area per 24hours), or on wounds where the level of exudate is moderate (e.g., 1.1 g(nominal) of liquid exudate/cm² of wound area per 24 hours). In someembodiments, exudate from the wound is managed by the dressingsdisclosed herein through a combination of absorption in the dressing andan evaporation of moisture through the dressing. In some embodiments,exudate from the wound is managed by the dressings disclosed hereinthrough absorption in the dressing or evaporation of moisture throughthe dressing. In embodiments where evaporation of exudate moisturethrough the dressing is intended, occlusive materials positioned overthe dressing area can impair the intended evaporation.

Overview of the Mechanical Aspects of the Pump System

The pump system embodiments described herein can have a compact, smallsize. In some embodiments disclosed herein, a pump assembly of the pumpsystem can have a diameter (e.g., equivalent diameter) or lateral sizebetween 15 mm and 35 mm, less than 15 mm, less than 25 mm, less than 35mm, or less than 50 mm. For example, in some embodiments, the pumpsystem can have a diameter or lateral size of 10 mm, 23 mm, or 40 mm, orcan have a diameter or lateral size in the range of approximately 26 mmto approximately 27 mm, between approximately 22 mm or smaller andapproximately 28 mm. In some embodiments disclosed herein, the pumpassembly can have a thickness or height of approximately 8 mm, betweenapproximately 6 mm and approximately 10 mm, or a thickness or height ofless than 20 mm. For example, in some embodiments, the thickness orheight of the pump assembly can be 5 mm, 12 mm, or 20 mm. For exampleand without limitation, in some embodiments the pump assembly can have avolume of approximately 6.2 cubic centimeters, between approximately 5.0cubic centimeters or less to approximately 7.0 cubic centimeters, or avolume of less than 10.0 cubic centimeters. For example, in someembodiments, the volume of the pump assembly can be 4.0 cubiccentimeters, 6.0 cubic centimeters, or 8.0 cubic centimeters. In someembodiments, the housing of can have a lateral size of approximately60.0 mm, between approximately 40.0 mm and approximately 80.0 mm, or alateral size of less than 90 mm, and a height of approximately 15.0 mm,between approximately 10.0 mm and approximately 20.0 mm, or a height ofless than 30 mm. For example, in some embodiments, the housing can havea Length×Width×Height dimension of 72 mm×66 mm×21 mm, approximately 72mm×66 mm×21 mm, 70-73 mm×64-67 mm×20-22 mm, or a Length×Width×Heightdimension of less than 90 mm×less than 90 mm×less than 30 mm. Forexample, in some embodiments, the Length×Width×Height dimension of thehousing can be 68 mm×62 mm×18 mm, 65 mm×78 mm×21 mm, 65 mm×79 mm×21 mm,or 80 mm×74 mm×25 mm. In some embodiments, the pump system can have amass of 150 grams, approximately 150 grams, between 100-150 grams, or amass of less than 200 grams, or a mass of less than 300 grams. Forexample, in some embodiments, the mass of the pump system can be 90grams, 125 grams, 150 grams, or 220 grams. Of course, the pump systemcan be any miniaturized size and have any mass and volume that ismanufacturable, and the overall power output and efficiency meet theneeded requirements for the desired application, within or outside ofwound therapy. As used herein, efficiency can be defined as (fluid powerout)/(electrical power in).

The pump system can be produced for a low cost and can operate at highefficiencies, making it beneficial for portable, disposable, and/orsingle use applications. This pump can optionally be used in anultra-portable single-use negative-pressure wound therapy (NPWT) device.In some embodiments, the pump system can run for 10 days on a smallprimary cell without the need for battery replacement or recharging. Insome embodiments the pump system can run up to 10 days on a 3V, 2000 mAhcell (e.g., with the pump working for about 20% of the time). In someembodiments, the pump system can be powered by two 1.5 volt, 2500-3000mAh batteries connected in series. In some embodiments, the pump systemcan run for a week on a small primary cell such as one or more batterieshaving a total capacity of 3000 mAh at 3V without the need for batteryreplacement or recharging. Additionally, in some embodiments, the pumpsystem can be subjected to X-ray scans during its use withoutinterfering with its function. For example, in some embodiments, thepump system can be worn during computed tomography (CT) scans,computerized axial tomography (CAT) scans, and the like.

FIGS. 1-8 illustrate multiple views of an embodiment of a pump system100 having an outer housing 102 and an optional mounting component 104,and FIGS. 73-80 illustrate additional views of the pump system 100 withthe optional mounting component 104 removed. As shown in the illustratedembodiment in FIGS. 1-8, the pump system 100 can include an outerhousing 102 for containing and/or supporting components of the pumpsystem 100. The outer housing 102 can be formed from one or moreportions, such as a front portion 102 a and a rear portion 102 b asshown in FIG. 1, which can be removably attached to form the outerhousing 102.

In some embodiments, the pump system 100 can optionally include amounting component 104 which can be designed to advantageously allow thepump system 100 to be mounted on another object such as, but not limitedto, a user's person. For example, FIGS. 81-88 illustrate multiple viewsof an optional mounting component 104 that can be attached to a pumpsystem 100, and which is shown attached to the pump system 100 in FIGS.1-8. In some embodiments, the mounting component 104 can include a clip106 (as shown in FIGS. 3-8) designed to retain the mounting component104 on a user's outerwear, such as on a user's pocket, a pouch, a belt,a flap, or otherwise. The clip 106 can be integrally formed with thebase 108 of the mounting component 104 such that the clip 106 canprovide a clamping force via resiliency of the material used to form theclip 106. In some embodiments, the clip 106 can be a separate componentfrom the base 108 and can include a biasing component, such as a coilspring, bent spring or the like, to provide a clamping force to retainthe clip 106 on the user's person. In some embodiments, the clampingforce can be low enough that a user can open the housing from theclamped position, but strong enough so that it will remain clamped aboutthe pocket, flap, or other material.

In some embodiments, the mounting component 104 can be removablyattached to the outer housing 102 such that the pump system 100 can beused with or without the mounting component 104. For example, FIGS. 1-8illustrate the pump system 100 with the optional mounting component 104,and FIGS. 73-80 illustrate the pump system 100 without the optionalmounting component 104. As shown in these figures, this can beneficiallygive the user the option to reduce the overall form factor of the pumpsystem 100 should the user decide to forego use of the optional mountingcomponent 104 as illustrated in FIGS. 73-80. Moreover, this canadvantageously allow a user to more easily replace one mountingcomponent with another mounting component should the user decide to doso. As shown in the illustrated embodiment, the mounting component 104can include one or more retention features, such as clasps 110 extendingfrom the periphery of the base 108, to retain the mounting component 104on portions of the outer housing 102. In the illustrated embodiment, themounting component 104 can be retained on the pump system 100 in a snapfit manner via use of the clasps 110. In some embodiments, the retentionfeatures can be mechanical fasteners such as screws, nuts, bolts,snap-fit connectors, or the like.

With continued reference to the pump system 100 of FIGS. 1-8, the outerhousing 102 can include a display 112 which can be designed to provide auser with information (e.g., information regarding an operational statusof the pump system 100). In some embodiments, the display 112 caninclude one or more indicators, such as icons 114, which can alert theuser to one or more operating and/or failure conditions of the pumpsystem 100. For example, the indicators can include icons for alertingthe user to normal or proper operating conditions, pump failure, powerfailure, the condition or voltage level of the batteries, the conditionor capacity of a wound dressing, detection of a leak within the dressingor fluid flow pathway between the dressing and the pump assembly,suction blockage, or any other similar or suitable conditions orcombinations thereof. An exemplary set of icons 114′ of a display 112′is illustrated in FIG. 56 which, from left to right, can include an “OK”indicator which can indicate normal operation of the pump system 100, a“leak” indicator which can indicate the existence of a leak in the pumpsystem 100 or components attached thereto, a “dressing full” indicatorwhich can indicate that a wound dressing is at or near capacity, and a“battery critical” indicator which can indicate that the battery is ator near a critical level. In some embodiments, the icons 114 or 114′ canhave a green and/or orange color, and/or can be illuminated with a greenand/or orange light (e.g., colored LEDs).

In the illustrated embodiment, one or more icons 114 can be printeddirectly on the display 112 of the outer housing 102. In someembodiments, one or more of the icons 114 can be provided on a labelattached to a portion of the outer housing 102. One or more of the icons114 can be illuminated when the status corresponding to that icon existsin the system. As will be discussed in further detail below, one or moreillumination components, such as LEDs, can be positioned within theouter housing 102 to illuminate the icons 114. To enhance illuminationof the icons using an illumination component within the outer housing102, portions of the outer housing 102 proximate and/or underlying oneor more of the icons 114 can be reduced in thickness to increase thetranslucency of the outer housing 102 proximate and/or underlying theicons 114. In some embodiments, portions of the outer housing 102proximate and/or underlying one or more of the icons 114 can be madefrom a transparent material. For example, in some embodiments, thedisplay 112 of the outer housing 102 can comprise an illumination panelthat is thinned and/or made of transparent and/or translucent material.Thinning portions of the outer housing 102 and/or making portions of theouter housing 102 from a transparent and/or translucent material canallow light from the illumination components to pass through the housing102 and illuminate the icons 114. Advantageously, as no openings areformed in the outer housing 102 to provide illumination for the one ormore icons 114 with a thinner or transparent and/or translucent housing,the potential for leakage around the icons 114 is eliminated or at leastsignificantly reduced.

In some embodiments, the pump housing can include a display integratedwith the housing such that the display includes part of the housing. Insome embodiments, the display can include one or more indicatorsconfigured to be illuminated by one or more corresponding illuminationsources positioned within the housing. In some embodiments, the one ormore illumination sources can include one or more light emitting diodes(LEDs). In some embodiments, the pump housing can also include anonhomogeneous thickness, the nonhomogeneous thickness including atleast a first thickness and a second thickness such that the firstthickness is less than the second thickness. In some embodiments, thefirst thickness can be proximate (e.g., adjacent) the second thickness.In some embodiments, a portion of the display can include the firstthickness and at least a portion of the housing proximate the displaycan include the second thickness. In some embodiments, a portion of thedisplay can include the one or more indicators. In some embodiments, aportion of the display can include translucent and/or transparentmaterial, wherein the transparent material is contiguous with theportion of the housing proximate the display.

To prevent the illumination of one icon from bleeding into andilluminating another icon, baffles can be positioned on one or moreportions of one or more interior surfaces of the outer housing 102proximate the one or more illumination components positioned within theouter housing 102. The baffles can be attached to and/or formedintegrally with interior surfaces of the outer housing 102 and/or withone or more components and/or surfaces of components positioned withinthe outer housing 102. For example, in some embodiments, the baffles cancomprise portions of the outer housing 102 that have not been reduced inthickness. In some embodiments, an integrally formed or separatelyattached baffle can surround the perimeter of each icon on the inside ofthe outer housing 102. Of course, any suitable baffle is appreciated andenvisioned, such as, for example, baffles integrally formed with theouter housing 102 having a reduced thickness but having a dark or opaquecolor relative to the transparent material underlying the one or moreicons 114. The skilled artisan will also appreciate that any suitablebaffle placement is envisioned. In some embodiments, more than one typeof baffle can be used and/or combined with one or more different typesof baffles. The baffles can inhibit (e.g., prevent) one or more of theillumination components from illuminating one or more of the icons 114when one or more of the illumination components are illuminated.Advantageously, the baffles can help reduce the potential of usersmisreading the icons by preventing light that was intended for one iconfrom erroneously illuminating another icon. For example, with referenceto the exemplary set of icons 114′ of display 112′ shown in FIG. 56, thebaffles can be positioned under the display 112′ so that each of thefour icons can be separately illuminated without bleeding light into oneof the three other icons.

With continued reference to the pump system 100 illustrated in FIGS.1-8, the pump system 100 can include one or more user input features,such as button 116, designed to receive an input from the user forcontrolling the operation of the pump system 100. In the embodimentshown, a single button is present which can be used to activate anddeactivate the pump system 100 and/or control other operating parametersof the pump system 100. For example, in some embodiments, the button 116can be used to activate the pump system 100, pause the pump system 100,clear indicators such as icons 114, and/or be used for any othersuitable purpose for controlling an operation of the pump system 100(e.g., by sequentially pushing on the button 116). The button can be apush style button that can be positioned on an outside, front surface ofthe housing. In other embodiments, multiple input features (e.g.,multiple buttons) can be provided on the pump system 100.

In some embodiments, the button 116 can be designed to eliminate or atleast reduce the potential for leakage around the button 116. In someembodiments, a peripheral portion of the button 116 can be placed in aninterference fit with a surrounding lip of the outer housing 102. Insome embodiments, the entirety or portions of the button 116 can beformed of a deformable material capable of forming a relatively hermeticseal when abutted against a surface, such as rubber, silicon, or anyother suitable material.

In some embodiments, the pump system 100 can include a connector 302 forconnecting a tube or conduit to the pump system 100. For example, asshown in FIGS. 57A and 57B, the connector 302 can be used to connect thepump system 100 to a dressing 950. As shown in the illustratedembodiment, the wound dressing 950 can include a port 952 for receivingan end of the conduit 954. In some embodiments, the port 952 can includea connector portion 953 for receiving the conduit 954. In someembodiments, the conduit 954 can be connected directly to the connector302 of the pump system 100. In some embodiments, such as that shown inFIG. 57A, an intermediate conduit 956 can be used and attached toconduit 954 via a connector, such as a quick release connector 958, 960.

In some embodiments, the pump system can be configured to operate in acanisterless system, in which the wound dressing, such as wound dressing950, retains exudate aspirated from the wound. Such a dressing caninclude a filter, such as a hydrophobic filter, that prevents passage ofliquids downstream of the dressing (toward the pump system). In otherembodiments, the pump system can be configured to operate in a systemhaving a canister for storing at least part of exudate aspirated fromthe wound. Such canister can include a filter, such as a hydrophobicfilter, that prevents passage of liquids downstream of the dressing(toward the pump system). In yet other embodiments, both the dressingand the canister can include filters that prevent passage of liquidsdownstream of the dressing and the canister.

As will be described in further detail below in connection with FIGS.13-17B, the connector 302 can be part of an intake manifold 300 of thepump system 100 which can form an initial fluid flow pathway through thepump system 100. As shown in the illustrated embodiment, the connector302 can include one or more retention features, such as threading,snap-fit mounts such as clips, bayonet mounts, or the like to moresecurely retain a connected component to the connector 302.

FIGS. 9-10 illustrate rear elevation views of an embodiment of the pumpsystem 100 without the optional mounting component 104 attached to theouter housing 102. As shown in the illustrated embodiment, the rearportion 102 b of the outer housing 102 can include a removable cover 118for placement over a cavity 120. The cavity 120 can include one or morerecesses 122 designed to receive one or more power sources, such asbatteries, for powering the device. In some embodiments, an outerperiphery 124 of the cavity 120 can include features which can cooperatewith respective features of the cover 118 to reduce the likelihood thatmoisture will enter the cavity 120. For example, in some embodiments,the outer periphery 124 can include a rib along the bottom periphery, aside periphery, a top periphery, and/or a combination of one or moreperipheries to reduce the likelihood of moisture ingress into the cavity120. In some embodiments, the outer periphery 124 can include a recessalong the bottom periphery, a side periphery, a top periphery, and/or acombination of one or more peripheries to redirect moisture, such aswater droplets, away from the cavity 120.

FIGS. 11-12 illustrate perspective views of an embodiment of a pumpsystem 100 with portions of the outer housing 102 removed to expose anembodiment of a circuit board 200, an intake manifold 300, and a sourceof negative pressure such as a pump assembly 400. FIG. 13 illustrates aperspective view of an embodiment of pump system 100 with a frontportion of the outer housing 102 removed as well as the circuit board200 to expose the intake manifold 300 and pump assembly 400. As shown inthe illustrated embodiment, the circuit board 200, the intake manifold300, and/or the pump assembly 400 can be positioned within and/orsupported by the outer housing 102.

The control board 200 can be designed to control the function of thepump system 100 such as the pump assembly 400. The control board 200,such as a printed circuit board assembly (PCBA), can be designed tomechanically support and electrically connect variouselectrical/electronic components of the pump system 100. For example, insome embodiments, the control board 200 can connect one or morebatteries 202 to the pump assembly 400 to provide power to operate thepump assembly 400. In some embodiments, the control board 200 caninclude a pressure monitor 204. The pressure monitor 204 can besupported by the control board 200 and can be designed to monitor alevel of pressure in a fluid flow passageway. The control board 200, inconjunction with the pressure monitor 204, can be designed to protectthe pump assembly 400 from exceeding a predefined threshold pressureand/or can be designed to maintain a target pressure at the wound.

The circuit board 200 can be designed to cut power to the pump assembly400 if the pressure reading reaches a predetermined value, and bedesigned to resume when the pressure level drops below the predeterminedvalue or a second predetermined value that can be higher or lower thanthe first predetermined value. Additionally, the control board 200 canbe programmed to prevent such over-pressurization.

In some embodiments, the control board 200 can include indicator lights,audible alarms, and/or a combination of such features. For example, insome embodiments, the control board 200 can include indicator lights inthe form of one or more LEDs 206. As discussed above in connection withFIGS. 1-8, the one or more LEDs 206 can be used to illuminate one ormore icons 114 of the display 112 on the outer housing 102. In someembodiments, each LED 206 can correspond to one or more icons 114. Insome embodiments, the control board 200 can have one or more features208 (e.g., pressure sensitive switch(es)) to receive an input from thecontrol button 116.

FIG. 13 illustrates a front perspective view of a pump system 100 with afront portion of the outer housing 102 removed as well as the controlboard 200, to expose the intake manifold 300 and the pump assembly 400.As shown in the illustrated embodiment, the manifold 300 and the pumpassembly 400 can be positioned within and/or supported by one or moreportions of the outer housing 102.

FIGS. 14-17B illustrate various views of the intake manifold 300 and thepump assembly 400. As shown in the illustrated embodiment, the intakemanifold 300 can be in fluid communication with an intake port 426(shown in FIGS. 21-22) of the pump assembly 400. The intake manifold 300can be formed from one or more portions, such as a top portion 301 a anda bottom portion 301 b, which can be removably attached to form theintake manifold 300. For example, as shown most clearly in FIG. 17A, thetop portion 301 a can be received within the bottom portion 301 b in afriction and/or interference fit. In some embodiments, the top portion301 a and the bottom portion 301 b can be a monolithic structure. Insome embodiments, the intake manifold 300 can include a connector 302 atan end of the top portion 301 a which can protrude from the outerhousing 102 to connect a tube or conduit to the intake manifold 300. Asdiscussed above, the connector 302 can include one or more retentionfeatures, such as the illustrated threading, to secure the tube orconduit to the connector 302 and reduce the likelihood of accidentaldetachment. The intake manifold 300 can include a sealing member 304,such as an O-ring, positioned around a top portion 301 a of the intakemanifold 300. The sealing member 304 can advantageously be positionedbetween the intake manifold 300 and the outer housing 102 to eliminateor reduce the potential for leakage around the intake manifold 300. Forexample, the sealing member 304 can be positioned within an extension126 of the outer housing 102 as shown in FIG. 17B. In some embodiments,the sealing member 304 can be made from silicon.

The intake manifold 300 can include a port 306 designed to be in fluidcommunication with the pressure monitor 204. For example, as shown inFIG. 17B, the port 306 can directly receive a portion of the pressuremonitor 204 within the port 306. This can beneficially reduce the totalamount of plumbing through the pump system 100 and/or reduce thepotential for leakage. The port 306 can be positioned on the bottomportion 301 b of the intake manifold 300 although it can also bepositioned along any other portion of the intake manifold 300 asdesired. The intake manifold 300 can include an outlet port 308 forconnection to the intake port 426 of the pump assembly 400. As shown inthe illustrated embodiment, the intake manifold 300 does not include acheck valve or one-way valve. In some embodiments, the intake manifold300 can include a check valve or one-way valve to allow flow into thepump system 100 but inhibit flow out of the pump system 100.

FIG. 18 illustrates a cross-section of an embodiment of a pump assembly400 in an assembled configuration. FIGS. 19-20 illustrate an explodedview of the pump assembly 400 illustrating these various components. Asshown in the illustrated embodiment, the pump assembly 400 can include acover 410, a pump housing 420, one or more valves 450, and a pumpchamber body 470. The one or more valves 450 can be used to control theflow of fluids through a diaphragm chamber 472 which can be definedbetween the pump chamber body 470 and a diaphragm 550. As will bediscussed in further detail below, the diaphragm 550 can move relativeto the pump chamber body 470 to alter the volume of the diaphragmchamber 472. This change in volume can result in changes in pressurewithin the diaphragm chamber 472 which can generate fluid flow into andout of the diaphragm chamber 472. For example, the one or more valves450 can be designed to alternately open and close in response to thechanges in pressure within the diaphragm chamber 472. The one or morevalves 450 can be designed to control the fluid flow through thediaphragm chamber 472 such that fluid enters from one or more intakeopenings and fluid is expelled from one or more exhaust openings whichcan be different from the intake openings.

As shown in the illustrated embodiment, the pump assembly 400 caninclude an upper pole 500, a lower pole 520, and a magnet 540. Themagnet 540 can provide a permanent magnetic field through at least aportion of the pump assembly 400. In some embodiments, the upper pole500 and/or the lower pole 520 can support the magnet 540. In someembodiments, the upper pole 500 and/or the lower pole 520 can bearranged to more effectively align the magnetic field with respect toone or more components of the pump assembly 400, such as a coil 600. Forexample, in some embodiments, the upper pole 500 and/or the lower pole520 can be arranged to shape the magnetic field of the magnet 540 sothat it is normal to any current that flows through the coil. In sodoing, the efficiency of the pump assembly 400 can advantageously beincreased. In some embodiments, the upper pole 500 and/or the lower pole520 can optionally include magnetic material.

As shown in the illustrated embodiment, the pump assembly 400 caninclude a voice coil actuator (VCA). The pump assembly 400 can include acoil 600 attached to a piston sub-assembly which can include a supportmember 650 designed to support the coil 600, a shaft 700, and/or aspring member 750. The pump assembly 400 can also include a bearing orbushing 800. The VCA can be used to generate vertical harmonic movementsof the shaft 700 by passing a current inside a wire fully absorbed inthe permanent magnetic field of the magnet 540. An electric current canflow through the coil 600 to generate a magnetic field such that amagnetic force can be applied to the coil 600 by virtue of the permanentmagnetic field provided by magnet 540. In some embodiments, the magneticforces applied to the coil 600 can be transferred to the support member650 and then to the diaphragm 550 through a mechanical connectionbetween the coil 600 and the support member 650. For example, thesupport member 650 and the spring member 750 can be designed to transmitforces applied to the coil 600 to the shaft 700, which can be connectedto the diaphragm 550, such that forces applied to the coil 600 areultimately transmitted to the diaphragm 550. By controlling the currentflow through the coil 600, movement of the diaphragm 550 can ultimatelybe controlled. In some embodiments, the spring member 750 can beattached to the shaft 700 to alter a resonance frequency for the pumpassembly 400 thereby enhancing efficiency around that frequency. In someembodiments, the bushing 800 can be used to help maintain alignment ofthe pump assembly 400 components during operation.

As noted above, FIGS. 19-20 illustrate an exploded view of the pumpassembly 400 illustrating various components such as a cover 410 and apump housing 420. In some embodiments, the pump housing 420 can beadapted to support and protect many of the components of the pumpassembly 400. The pump housing 420 can have one or more air channels,such as intake channel 422 and exhaust channel 424, formed in and/oralong an outer surface of the pump housing 420 as shown most clearly inFIG. 22.

The intake channel 422 can be used to channel or communicate fluid, suchas air, from an intake port 426 which can be in communication with awound dressing via the connector 302 towards an inlet opening 427 for anintake valve chamber formed between the pump housing 420 and the pumpchamber body 470 and in which the intake valve resides. The exhaustchannel 424 can be used to channel or communicate fluid, such as air,from an outlet opening 429 for an exhaust valve chamber formed betweenthe pump housing 420 and the pump chamber body 470 and in which theexhaust valve resides. The exhaust channel 422 can channel orcommunicate such fluid towards an exhaust port 428 and into an interiorof a chamber 430 where it can eventually be exhausted into theatmosphere within the outer housing 102. As will be discussed in furtherdetail below, chamber 430 can form part of a noise reduction system forthe pump assembly 400 to reduce the amount of noise generated by thepump assembly 400 during operation. As shown in the illustratedembodiment, the chamber 430 can include one or more ribs 431.

The cover 410 can be positioned over the outer surface of the pumphousing 420. The cover 410 can be an adhesive backed foil, film, paper,plastic sheet or label, or other similar object. In some embodiments,the cover 410 can be a thermal transfer polyester such as 3M's 7815 witha topcoat such as FLEXcon's Compucal Excel 10442. In some embodiments,the cover 410 can be a plate made from plastic, metal, or the like andcan include a gasket for positioning between the cover 410 and the outersurface of the pump housing 420 to enhance the seal between the cover410 and the outer surface of the pump housing 420. The cover 410, whenpositioned over the outer surface of the pump housing 420, can cooperatewith intake and exhaust channels 422, 424 to form enclosed airpassageways. For example, in some embodiments, the cover 410 can bedesigned to prevent an air short-circuit between the intake and exhaustchannels 422, 424. In some embodiments, the cover 410 can bemonolithically formed with the outer surface of the pump housing 420.

With reference to FIG. 21, the pump housing 420 can include one or moreadditional openings 432 to allow for components to pass from one side toanother. For example, as will be discussed in further detail below, theone or more openings 432 can be used to allow an electrical conduit 604to connect the coil 600 to the circuit board 200. The openings 432 canalso be used to allow for additional clearance for pump assembly 400plumbing, electronics such as wiring, and the like. For example, in someembodiments, the openings 432 can be used to allow a flexible circuitboard to connect to a main circuit board by allowing the flexiblecircuit board to extend through the openings 432. For example, as shownin FIG. 14, an electrical conduit 604 can extend from an additionalopening 432 so that the electronics inside the pump assembly can beelectrically connected to the main circuit board 200 (shown in FIG. 11)of the pump system 100 (shown in FIG. 11). In this and other ways, aswill be appreciated by the skilled artisan, the openings 432 canadvantageously facilitate the management of wires within and around thepump housing 420. In some embodiments, the pump housing 420 can includeone or more indexing features, such as the illustrated cutouts 434,which can be designed to facilitate assembly and ensure that componentsare properly oriented when assembled. In some embodiments, the pumphousing 420 can be made from plastics such as polycarbonate, metals,composites, or the like, or a combination of materials.

FIGS. 23-24 illustrate various views of an embodiment of a valve 450which can be used with the pump assembly 400. The valve 450 can have aflexible and/or deflectable tab portion or member 452 supported in amiddle portion of the valve 450. The tab portion 452 can be surroundedalong its periphery by a frame portion 454 and can be attached to theframe portion 454 via a neck 456 extending from the tab portion 452. Asshown in the illustrated embodiment, an opening or gap 458 can existbetween the tab portion 452 and the frame portion 454 to facilitate thepassage of fluid around the tab portion 452 and past the valve 450. Insome embodiments, the opening or gap 458 can have a width ofapproximately 0.4 mm, or from approximately 0.3 mm to approximately 0.5mm, and can surround approximately 80% of a perimeter of the tab portion452.

As shown in the illustrated embodiment, the tab portion 452 can besupported in cantilever fashion via the neck portion 456, such that thetab portion 452 can bend or deflect away from a relaxed or closedposition as shown in FIGS. 23-24. In some embodiments, the valve 450 canhave one or more hinges, joints, articulations, or curves therein at oradjacent to the neck portion 456 of the tab portion 452 to improve theability of the tab portion 452 to bend and deflect, thereby potentiallyimproving the efficiency of the valves. In some embodiments, the valvesand valve supports can be configured such that the valves are biasedagainst the intake side of the valve or valve supports for improved sealand pump efficiency. As discussed above, movement of the diaphragm 550can cause the valves to move in opposite directions away from theirrespective bias. In some embodiments, the valves can be designed suchthat some degree of leakage past the valve occurs under low pressureconditions. For example, in some embodiments, the valves 450 can bedesigned to leak at a rate of between about 0.1 mL/min to about 10mL/min, or a leak rate of less than 10 mL/min, at low pressureconditions, between about 0.1 mL/min to about 5 mL/min, or a leak rateof less than 5 mL/min, at low pressure conditions, between about 0.1mL/min to about 2 mL/min, or a leak rate of less than 2 mL/min, at lowpressure conditions, any subrange within these ranges, or any otherleakage rate as desired. Such leakage can facilitate sterilization ofthe device.

As shown in the illustrated embodiment, the valve 450 can include one ormore indexing features, such as alignment tabs 460 a, 460 b, which canbe matched to corresponding indexing features on another component, suchas the pump chamber body 470. This can advantageously facilitate theplacement, securement, and alignment of the valve 450 relative to thecomponent. As shown in the illustrated embodiment, the alignment tabs460 a, 460 b can extend from a periphery of the frame portion 454 andcan have different shapes to reduce the likelihood of improperinstallation. In some embodiments, the valve member 450 can have justone alignment tab, such as alignment tab 460 a or 460 b.

As shown in the illustrated embodiment, the valve 450 can have a raisedsurface or rib 462 (also referred to as a compression ring) extendingaway from a surface of the valve 450. As shown in the illustratedembodiment, the rib 462 can be positioned along a periphery of the frameportion 454. The rib 462 can advantageously function as a spacer toensure that a gap exists between the tab portion 452 and an exhaust sideof the valve 450 such that the tab portion 452 has adequate space tobend or deflect to an open position. The rib 462 can also advantageouslyfunction to create a preload (also referred to as bias) against an inletor exhaust nozzle to increase the seal between the valve and the nozzle.As discussed above, in some embodiments, the valve 450 can be secured(also referred to as sandwiched) between a pump chamber body and thepump housing such that the valve is compressed between the pump chamberbody and the pump housing. In some embodiments, as will be described infurther detail below, the pump chamber body can be laser welded to thepump housing. When the valve 450 is secured, the rib 462 can compress.In some embodiments, compression of the rib 462 allows the preload toform against the inlet and exhaust nozzles.

For example, in some embodiments, compression of the rib 462 preloadsthe tab portion 452 in a direction away from the rib, such as, forexample, toward the intake sides of the inlet or exhaust nozzleopenings. The tab portion 452 can be designed to inflect (also referredto as flex) itself until it contacts the nozzle planes of the inletexhaust openings when the rib 462 is compressed. For example, withreference to FIGS. 23, 25, and 26, the valve 450 can be placed in theintake and exhaust recesses 476 a, 476 b such that the rib 462 facestoward the surface of the intake recess 476 a and faces away from thesurface of the exhaust recess 476 b. When the rib 462 is compressed, thetab portion 452 of the valve 450 in the intake recess 476 a is forcedtoward the inlet opening in the pump housing, and the tab portion 452 ofthe valve 450 in the exhaust recess 476 b is forced toward the exhaustopening in the pump chamber body 470. In this way, the tab portion 452of the one or more valves 450 can interfere with the inlet and exhaustnozzles such that the tab portion is biased across the planes of theinlet and exhaust nozzles.

In some embodiments, the valve 450 can be made from polymers such asrubbers, silicon, or the like, or a combination of materials. In someembodiments, the valve 450 can be dimensioned to meet a desired initialpreload and total stiffness. The initial preload can be designed so asto provide a seal against the nozzles. For example, in some embodiments,the valve 450 can have an initial preload against the inlet or exhaustnozzle of approximately 0.03 millimeters and can have a total stiffnessof about 12 Newtons/meter, although any suitable initial preload andtotal stiffness is envisioned.

FIGS. 25-27 illustrate various views of an embodiment of a pump chamberbody 470 which can form part of the pump assembly 400. The pump chamberbody 470 can cooperate with the diaphragm 550 to form a diaphragmchamber 472 (shown in FIG. 18). Via movement of the diaphragm 550relative to the pump chamber body 470, the diaphragm 550 can effectivelyalter the volume of the diaphragm chamber 472 to generate fluid flowinto and out of the diaphragm chamber 472.

As discussed above, the fluid flow into and out of the diaphragm chamber472 can be controlled by the one or more valves 450, which can bedesigned to passively move in response to the volume and pressurechanges within the diaphragm chamber. For example, in some embodiments,the tab portions 452 of the one or more valves 450 can passively move inresponse to the volume and pressure changes within the diaphragmchamber. In some embodiments, the volume inside the diaphragm chamber472 can increase when the shaft 700 moves the diaphragm 550 (e.g., bydeforming it) away from the pump chamber body 470 (e.g., toward thebushing 800). This increase in volume can generate a vacuum condition byreducing the pressure inside of the diaphragm chamber 472 below thesurrounding atmospheric pressure. When the shaft 700 moves to create avacuum condition, it can be said to be in suction travel. For example,during suction travel, the shaft 700 can move the diaphragm 550 downwardand/or away from the inlet and exhaust nozzles of the pump chamber body470 and/or toward a bottom dead center (BDC) of the pump assembly 400.When a vacuum condition forms in the diaphragm chamber 472 as a resultof suction travel of the shaft 700, the inlet valve can open and theoutlet valve can close. For example, the vacuum condition can cause thetab portion of the inlet valve to move away from the nozzle plane of theinlet nozzle, thereby opening the inlet valve, and can cause the tabportion of the outlet valve to be pushed against the nozzle plane of theexhaust nozzle, thereby closing the outlet valve. Similarly, in someembodiments, the volume inside the diaphragm chamber 472 can decreasewhen the shaft 700 moves the diaphragm 550 (e.g., by deforming it)toward the pump chamber body 470 (e.g., away from the bushing 800). Thisdecrease in volume can generate an overpressure condition by increasingthe pressure inside of the diaphragm chamber 472 above the surroundingatmospheric pressure. When the shaft 700 moves to create an overpressurecondition, it can be said to be in pumping travel. For example, duringpumping travel, the shaft 700 can move the diaphragm 550 upward and/ortoward the inlet and exhaust nozzles of the pump chamber body 470 and/ortoward a top dead center (TDC) of the pump assembly 400. When anoverpressure condition forms in the diaphragm chamber 472 as a result ofpumping travel of the shaft 700, the outlet valve can open and the inletvalve can close. For example, the overpressure condition can cause thecause the tab portion of the outlet valve to move away from the nozzleplane of the exhaust nozzle, thereby opening the outlet valve, and cancause the tab portion of the inlet valve to be pushed against the nozzleplane of the inlet nozzle, thereby closing the inlet valve.

As a result of pressure changes within the diaphragm chamber 472 causedby the suction and pumping travel of the shaft 700, in some embodiments,the inlet and exhaust valves can synchronously move in oppositedirections with respect to each other when they open and close (e.g.,when the inlet and outlet valves are both positioned on the inside oroutside of a diaphragm chamber defined between the diaphragm and thepump chamber body), or can synchronously move in the same direction withrespect to each other when they open and close (e.g., when the inlet andoutlet valves are positioned such that one is on the inside of thediaphragm chamber and one is positioned on the outside of the diaphragmchamber defined between the diaphragm and the pump chamber body).

In some embodiments, the inlet and exhaust valves can have nearsynchronous movement in which the inlet or outlet valve closes beforethe other valve opens. This asynchronous movement (also referred to asnear synchronous movement) can be the result of the preload of the tabportion 452 of the one or move valves 450 against the intake sides ofthe inlet and exhaust nozzle openings of the pump chamber body 470 asdescribed above. The amount of preload can be the same or different forthe inlet and outlet valves. In some embodiments, the preload canrepresent the amount of force that the pressure in the diaphragm chambermust overcome to open the inlet and outlet valves. For example, theforces associated with the preloads of the tab portions of inlet andoutlet valves can correspond to the threshold pressures that arerequired to open the inlet and outlet valves, respectively. Thethreshold pressures can be any suitable pressure differential relativeto any suitable reference pressure, such as, for example, −10 mmHg forthe inlet valve and 10 mmHg for the outlet valve, where 0 mmHg is thereference atmospheric pressure.

For example, during suction travel of the shaft 700, an inlet valve 450can open under a specific change in pressure (e.g., −10 mmHg) while anoutlet valve 450 is pushed against the nozzle plane of the outlet nozzleto seal (also referred to as close) the outlet, and during pumpingtravel of the shaft 700, an outlet valve 450 can open under a specificchange in pressure (e.g., 10 mmHg) while an inlet valve is pushedagainst the nozzle plane of the inlet nozzle to seal (also referred toas close) the inlet. When a vacuum condition is caused by suction travelof the shaft 700, the outlet valve can close before the inlet valveopens because it takes a short amount of time for the vacuum conditionto form within the diaphragm chamber to overcome the preload of theinlet valve following an overpressure condition. Similarly, when anoverpressure condition is caused by pump travel of the shaft 700, theinlet valve can close before the outlet valve opens because it takes ashort amount of time for the overpressure condition to form within thediaphragm chamber to overcome the preload of the outlet valve followinga vacuum condition. As discussed, when vacuum and overpressureconditions generated by diaphragm movement exceed the amount of thepreload, the tab portions 452 of the inlet and exhaust valves 450 canopen. This can allow fluid to flow into and out of the diaphragm chamber472. In addition to the preload against the inlet and exhaust nozzleopenings helping to seal the valve against the nozzles, the valves 450can also be designed such that the vacuum and overpressure conditionsgenerated within the diaphragm chamber 472 during pumping action helpspush the tab portions 452 of the inlet and exhaust valves against theinlet and exhaust nozzles.

In some embodiments, to control the flow of fluid into and out of thediaphragm chamber 472, the pump assembly 400 can include one or morevalves, such as valves 450. In some embodiments, the pump chamber body470 can include a valve support portion 474 designed to receive andsupport one or more valves of the pump assembly 400. As discussed above,in some embodiments, the one or more valves 450 can be secured betweenthe pump chamber body 470 and the pump housing 420. In some embodiments,the placement of the one or more valves between the pump chamber body470 and the pump housing 420 can define one or more correspondingpre-chambers adjacent the diaphragm chamber 472 between the pump chamberbody 470 and the pump housing 420. In some embodiments, the pre-chamberscan be sealed to avoid short-circuits of air between them by a laserwelding process that can connect the pump chamber body 470 to the insideof the pump housing 420.

As shown in the illustrated embodiment, the valve support portion 474can include one or more recesses, such as an intake or inlet recess 476a and exhaust or outlet recess 476 b, formed along a surface 475 of thevalve support portion 474. The recesses 476 a, 476 b can be designed toreceive and support one or more valves. In some embodiments, therecesses 476 a, 476 b are larger than the valves that they are designedto receive. The larger recesses can advantageously function toaccommodate for the material deformation that can occur when the valveis compressed. The inlet recess 476 a can include an inlet opening 478 awhich can be in fluid communication with the diaphragm chamber 472. Theinlet recess 476 a can cooperate with an intake valve to allow fluidpassage into the diaphragm chamber 472 during an intake phase of thepump assembly 400. The outlet recess 476 b can include an outlet opening478 b which can be in fluid communication with the diaphragm chamber472. The outlet recess 476 b can cooperate with an exhaust valve toallow fluid passage into the diaphragm chamber 472 during an exhaustphase of the pump assembly 400. In some embodiments, surface 475 can bedesigned to be positioned proximate or adjacent an inner surface of thepump housing 420. Accordingly, the inner surface of the pump housing 420can cooperate with inlet recess 476 a to form an intake valve chamberand an exhaust valve chamber via outlet recess 476 b. In someembodiments, a sealant or gasket can be positioned between the surface475 and an inner surface of the pump housing 420 to enhance the sealbetween the two components.

In some embodiments, the pump chamber body 470 can be welded, such aslaser welded, to the pump housing 420. For example, a laser beam can beused to weld an absorber material of the pump chamber body 470 to atransparent material of the pump housing 420 by heating up the absorbermaterial to its melting point after passing through the transparentmaterial. The transparent material can allow the laser to pass throughthe pump housing and heat the absorber material on and/or within thepump chamber body. Similarly, the absorber material can include anysuitable laser absorbing pigment that facilitates the absorption oflight from the laser such that the temperature of the absorber materialcan be increased to its melting point. Whereas the transparent materialcan allow the laser to pass through, the absorber material can allow thelaser to be absorbed. To facilitate absorption of energy from the laser,and to in turn increase the temperature of the absorber material to itsmelting point, the absorber material can include a pigment that absorbsthe wavelength(s) of light emitted by the laser. In some embodiments,the pigment of the absorber material can be darker relative to thetransparent material. For example, in some embodiments, the absorbermaterial can have a well-defined percentage of black pigment, such as,for example, between 1%-10% black pigment, between 1%-100% blackpigment, between 5%-100% black pigment, between 50%-100% black pigment,between 80%-100% black pigment, between 90%-100% black pigment, orbetween any other suitable percentages, or less than 100% black pigment,less than 90% black pigment, less than 50% black pigment, less than 15%black pigment, or less than any other suitable percentage. For example,in some embodiments, the percentage of black pigment in the absorbermaterial can be 1%, 30%, 80%, 95%, 100%, or any other suitablepercentage. In some embodiments, the higher the percentage of laserabsorbing pigment that the absorber material has, the faster theabsorber material will melt for any given laser intensity. In someembodiments, only the portion of the pump chamber body 470 that is to bewelded to the pump housing 420 is black. During the welding process, thepump housing 420 and the pump chamber body 470 can be held together witha constant, increasing, or decreasing pressure to prevent the twocomponents from moving in any dimension relative to one another using,for example, a clamp. For example, in some embodiments, a spring clampor an air-operated clamp can be used, although any suitable tensionproviding clamp is envisioned. While the pump housing 420 and the pumpchamber body 470 are held together, a laser beam can be guided along adesigned melt contour. For example, in some embodiments, the pumpchamber body 470 can have a laser absorbing pigment along the meltcontour. The resultant melt contour represents the laser weld betweenthe pump housing and the pump chamber body. In some embodiments, themelt contour 490 that connects the pump housing and the pump chamberbody together can be designed as shown in FIG. 58. Of course, any othersuitably shaped contour is envisioned. Once the melt contour solidifies,a strong connection between the pump chamber 470 and pump housing 420 iscreated. In some embodiments, the transparent and absorbent materialscan be chosen such that they are chemically compatible. For example, thetransparent and absorbent materials can be different pigments of thesame molecules. With reference to FIG. 19, the pump chamber body 470 canbe laser welded to the pump housing 420 from the underside of the pumphousing 420. In some embodiments, the intake and outtake channels on thesurface of the pump housing 420 can be sloped (as shown in FIG. 22) toprevent sudden changes in laser diffraction when the laser passes overthe channels during the welding process. For example, the intake andexhaust channels 422, 424 can have one or more sloped portions 435 asshown in FIG. 22. In some embodiments, the one or more sloped portions435 can have straight and/or curved profiles.

As shown in the illustrated embodiment, the recesses 476 a, 476 b canhave one or more indexing features, such as the recesses 480 a, 480 b,sized and shaped to receive corresponding indexing features of thevalve, such as alignment tabs 460 a, 460 b of the valve member 450. Thepositioning of the alignment tabs 460 a, 460 b and the recesses 480 a,480 b can ensure that the valve members 450 will be in the properorientation and alignment when positioned in the recesses 476 a, 476 b.As should be noted, in some embodiments, the same valve 450 can functionas either an intake valve or an exhaust valve depending on theorientation of the valve 450. Accordingly, the position of the alignmenttabs 460 a, 460 b and recesses 480 a, 480 b can ensure that the valve450 is properly oriented to function as an intake valve or an exhaustvalve depending on the recess, such as inlet recess 476 a or outletrecess 476 b, in which the valve 450 is placed. Proper placement of thevalve 450 can ensure that the rib 462 will be facing in a desireddirection and that the tab portion 452 will cover an appropriate openingwhen in a relaxed or closed state such as the inlet opening of the pumphousing 420 outlet opening 478 b of the pump chamber body.

Moreover, as shown in the illustrated embodiment, the pump chamber body470 can include one or more indexing features, such as bosses 481, whichcan be matched to corresponding indexing features on another component,such as the cutouts 434 of the pump housing 420. In some embodiments,the pump chamber body 470 can be made from plastics such aspolycarbonate, metals, composites, or the like, or a combination ofmaterials.

FIGS. 28-31 illustrate various views of an embodiment of a diaphragm 550which can form part of the pump assembly 400. As shown in theillustrated embodiment, the diaphragm 550 can include a connectionportion 560 and a peripheral portion 570. In some embodiments, theconnection portion 560 can be positioned generally along an axialcenterline of the diaphragm 550 such that the connection portion 560 isgenerally centered on the diaphragm 550. The connection portion 560 caninclude a recess 562 into which another component, such as the shaft700, can be inserted. In some embodiments, diaphragm 550 can be designedto help maintain the radial alignment of the shaft 700 with theremainder of the pump assembly 400. The recess 562 can include anundercut portion 564 thereby forming a lip 566 around at least aperiphery of the recess 562. In some embodiments, the undercut portion564 can have a radius that is configured to reduce the amount of stressthat is applied to the diaphragm. The lip 566 can advantageouslyreleasably secure the other component, such as the shaft 700, to thediaphragm 550 such that movement of the other component can result inmovement of the diaphragm 550. As shown in the illustrated embodiment,the lip can include filleted and/or chamfered edges which can enhancethe lifespan of the diaphragm 550. For example, the filleted edgesand/or chamfered edges can reduce the amount of stress applied to theconnection portion 560 as the diaphragm 550 is removed from a productiontool.

As shown in the illustrated embodiment, the peripheral portion 570 caninclude a body portion 572, in the form of an annular ring, and a lip574 extending from a bottom surface of the body portion 572. The lip 574can be formed integrally with the body portion 572. The increasedthickness that results from the lip 574 can improve the sealability ofthe peripheral portion 570 of the diaphragm and hence improve thesealability of the diaphragm 550.

As shown in the illustrated embodiment, the connection portion 560 canbe attached to the peripheral portion 570 via a web 580. The web 580 canbe sized and shaped to allow the connection portion 560 to move relativeto the peripheral portion 570 to allow an interior volume 552 of thediaphragm 550 to be altered. In some embodiments, the web 580 can bemade out of a resilient material having a suitable modulus ofelasticity. This can allow the web 580 to temporarily deform in responseto forces exerted on the web 580. In some embodiments, the web 580 canbe designed with excess material to allow for relative movement betweenthe connection portion 560 and the peripheral portion 570. For example,as shown in the illustrated embodiment, the web 580 has excess materialsuch that the web 580 has some slack and takes on a curved shape in aninitial configuration. Should the connection portion 560 be moved awayfrom the peripheral portion 570, the web 580 can straighten to somedegree via loss of slack in the web 580. In some embodiments, it can beadvantageous to reduce the radius of the connection portion 560 relativeto the peripheral portion 570 to increase total length of the web 580.This can beneficially enhance the longevity of the diaphragm 550 whichcan be subjected to constant and cyclical motion. In some embodiments,it can be advantageous to increase the radius 582 of the web 580proximate the connection portion 560 when the web 580 is in an initialconfiguration such as is shown in FIGS. 28-31. For example, the radius582 can be increased so that the junction between the web 580 and theconnection portion 560 is thicker. This can reduce the strain at thejunction between the web 580 and the connection portion 560, which canin turn reduce fatigue and decrease the likelihood of the diaphragm 550breaking near or around the radius 582. In some embodiment, the radius582 can be uniform or can get progressively larger closer to theconnection portion 560. In some embodiments, it can be advantageous todecrease the diameter of the connection portion 560 so that the lengthof the web 580 can be increased. Similarly, in some embodiments, it canbe advantageous to increase the thickness and/or radius of the web 580between the connection portion 560 and the peripheral portion 570. Thiscan reduce the strain of the web 580 between the connection portion 560and the peripheral portion 570, which can in turn reduce fatigue anddecrease the likelihood of the diaphragm 550 breaking between theconnection portion 560 and the peripheral portion 570 of the web 580. Insome embodiments, the diaphragm 550 can be made from polymers such asrubbers, silicon, or the like, or a combination of materials.

FIGS. 32-33 illustrate various views of an embodiment of a spacer 590which can form part of the pump assembly 400. In some embodiments, thespacer 590 can be positioned above diaphragm 550 when in an assembledstate to maintain the diaphragm 550 in position relative to the pumpchamber body 470. For example, the spacer 590 can be positioned suchthat the spacer 590 maintains the diaphragm 550 in compression againstthe pump chamber body 470 thereby maintaining sealing engagement betweenthe diaphragm 550 and the pump chamber body 470.

As shown in the illustrated embodiment, the spacer 590 can include abody portion 592 such as the illustrated ring. The body portion 592 caninclude one or more alignment tabs 594 extending from the body portion592 which can facilitate positioning and orientation of the spacer 590within the pump assembly 400. For example, the alignment tabs 594 cancorrespond to slots 482 formed on the pump chamber body 470 (as shown inFIG. 25). In some embodiments, the body portion 592 can include aradially inward protrusion 596 to increase the surface area of thecontact surface 598 between the body portion 592 and the diaphragm 550.This can reduce the localized stress applied to the diaphragm 550 alongthe contact surface 598 and reduce the likelihood of failure of thediaphragm 550. In some embodiments, the spacer 590 can be made frommaterials such as plastics, metals, composites, or the like, or acombination of materials. In some embodiments, the spacer 590 can bemade from polyphenylene ether (PPE).

With reference back to FIGS. 18-20, the pump assembly 400 can include amagnetic assembly which can include an upper pole 500, a lower pole 520,and a magnet 540. One or both of the upper pole 500 and lower pole 520can support the magnet 540. In some embodiments, the arrangement and/orplacement of the upper pole 500 and/or lower pole 520 beneficially alignthe magnetic field of the magnet 540 to enhance the efficiency of thepump assembly 400. Such alignment of the magnetic field can improveefficiency of the pump assembly 400. Details regarding the alignment ofthe magnetic field are described in greater detail in U.S. PublicationNos. 2013/0331823 and International Patent Publication No. 2013/171585,both of which have been hereby incorporated by reference in theirentireties as if made part of this disclosure.

The upper pole 500 can have an opening 502 formed through an axialcenterline of the upper pole 500. The bushing 800 can be positionedwithin the opening 502 and/or supported by the upper pole 500. In someembodiments, the upper pole 500 can include a first portion 504 and asecond portion 506 extending transverse to the first portion. As shownin the illustrated embodiment, the first portion 504 can be generallyplanar and extend in a direction generally perpendicular to the axialcenterline of the upper pole 500. The second portion 506 can extend awayfrom the first portion 504 in a direction generally parallel to theaxial centerline at approximately a 90 degree angle relative to thefirst portion 504. In some embodiments, the second portion 506 canextend away from the first portion 504 at an angle greater than or lessthan a 90 degree angle relative to the first portion 504, such as, butnot limited to, between about 10 degrees to about 170 degrees, betweenabout 30 degrees to about 150 degrees, between about 45 degrees to about135 degrees, between about 60 degrees to above 120 degrees, anysubranges within these ranges, or any other degree relative to the firstportion 504 as desired. In some embodiments, the upper pole 500 can bemade from materials such as mild steel, a sintered soft magnetic metalsuch as GKN 72-IBP2 (S-FeP-130), or sintered steel (or any suitablemagnetic or ferromagnetic material).

The lower pole 520 can include an opening 522 formed through an axialcenterline of the lower pole 520. The opening 522 can be sized andshaped such that the second portion 506 of the upper pole 500 can passtherethrough. As shown in the illustrated embodiment, the lower pole 520can be spaced apart from the upper pole 500 and can be supported by thepump housing 420. The lower pole 520 can be made from mild steel, asintered soft magnetic metal such as GKN 72-IBP2 (S-FeP-130), orsintered steel (or any suitable magnetic or ferromagnetic material).

The magnet 540 can be positioned between the upper pole 500 and thelower pole 520. The magnet 540 can have an opening 542 formed through anaxial centerline of the magnet 540. In some embodiments, a top surfaceof the magnet 540 can be positioned proximate or adjacent a bottomsurface of the first portion 504 of the upper pole 500. In someembodiments, a bottom surface of the magnet 540 can be positionedproximate or adjacent a top surface of the lower pole 520. In someembodiments, the magnet 540 can be positioned such that the secondportion 506 of the upper pole 500 extends through the opening 542 of themagnet 540. In such an arrangement, the magnetic field can be shiftedaway from the first portion 502 of the upper pole 500 and closer to thecenter of the coil 600. The magnet 540 can be made fromNeodymium-Iron-Boron (NdFeB)—N 45 M, Neodymium N33, or any othersuitable material magnetic material. This material can be used tomaximize field strength and minimize losses, thereby increasing theefficiency of the pump assembly 400.

With continued reference to FIGS. 18-20, the pump assembly 400 caninclude a coil 600. The coil 600 can have a body 602 formed from alength of wound conductive wire, such as without limitation copper wireor any other electrically conductive material. Accordingly, uponapplication of a current through the body 602, a magnetic field can begenerated generally directed along a direction parallel to an axialcenterline for the coil 600. As should be understood, the direction ofthe magnetic field can be reversed by reversing the direction of currentflow through the coil 600. To provide current to the coil 600, anelectrical conduit 604 can be connected to both ends of the coil 600. Insome embodiments, the electrical conduit 604 can be a flexible printedcircuit (FPC) attached to the circuit board 200. Other types ofelectrical conduits 604, such as elongate wires, can also be used.

As shown in the illustrated embodiment, the coil 600 can have an opening606 which can be sized and shaped to allow the second portion 506 of theupper pole 500 to pass therethrough. As shown FIG. 18, the coil 600 canbe positioned between the upper pole 500 and the lower pole 520 andpositioned proximate the magnet 540. Accordingly, as the voltagesupplied to the coil 600 oscillates between a positive voltage and anegative voltage, the coil 600 can oscillate up and down in the pumpassembly 400 between the two poles 500, 520.

In some embodiments, the coil 600 can be formed by winding approximately160 turns of wire, or from approximately 100 turns or less to 200 turnsor more of wire, which can be but is not required to be, 42 gauge(approximately 0.102 mm diameter) wire. For example, in someembodiments, the coil 600 can be formed by winding approximately 144turns of wire. In some embodiments, Lorentz's law can be used todetermine the appropriate number of turns of wire that are needed sothat the desired level of force is applied to the coil 600 when currentpasses through the coil 600. The wire used can be self-bonding wire thatbonds to adjacent sections of wire upon application of heat. The wirecan also be non-self-bonding wire. In some embodiments, approximately200 turns of wire, or up to approximately 260 turns of wire, can be usedto form the coil. Increasing the number of turns of wire can potentiallyreduce ohmic losses and improve the overall efficiency of the pumpassembly 400 by between approximately 22% and approximately 24%. As thenumber of turns of wire is increased, thereby increasing the efficiencyof the pump, the size or thickness of the magnet can be decreased,thereby reducing the magnetic field outside of the pump assembly 400that can potentially interfere with the function of pacemakers and otherimplanted cardiac devices (ICDs). [0178] FIGS. 34-35 illustrate anembodiment of a support member 650, such as a spider, which can bedesigned to support the coil 600 and connect the coil 600 to othercomponents of the pump assembly 400 such as the diaphragm 550. As shownin the illustrated embodiment, the support member 650 can include aperipheral portion 660 with longitudinally extending fingers 662. Thefingers 662 can be received within the opening 606 of the coil 600. Insome embodiments, the protrusions 662 can be sized and positioned suchthat the protrusions 662 are received within the opening 606 in afriction and/or interference fit to maintain the coil 600 in a desiredposition relative to the support member 650. In some embodiments, thecoil 600 can be affixed to the support member 650 via a mechanicalfastener and/or chemical fastener, such as an adhesive. The peripheralportion 660 can include a ring 664 which can have one or more raisedplatforms 666 extending from a surface of the annular ring 664. Theraised platforms 666 can be designed to space the coil 600 from theannular ring 664.

As shown in the illustrated embodiment, the support member 650 caninclude a base portion 670 attached to the peripheral portion 660 viaone or more arms 672. The arms 672 can be aligned with the slots 482 ofthe pump chamber body 470, the slots 508 of the upper pole 500, and/orslots between wall members 804 on the bushing 760. In some embodiments,the arms 672 can be sized and/or shaped with respect to such slots tolimit rotation along an axial centerline of the support member 650during operation of the pump assembly 400. The arms 672 can be designedto be relatively rigid to limit the amount of flex in the arms 672 whenthe peripheral portion 660 is moved relative to the base portion 670 andvice versa.

The base portion 670 can include an opening 674 for allowing anothercomponent of the pump assembly 400, such as the shaft 700, to passtherethrough. As shown in the illustrated embodiment, the opening 674can include a collet 676, or other form of clamping member, to moresecurely fasten the component to the base portion 670 in an interferenceand/or friction fit. The base portion 670 can include one or moreindexing features, such as openings 678, to facilitate positioning andalignment of the base portion 670 relative to other components of thepump assembly 400, such as the shaft 700.

FIGS. 36-37 illustrate various views of an embodiment of a shaft 700which can form part of the pump assembly 400. The shaft 700 can includea first end portion 710, an intermediate portion 720, and a second endportion 730. In some embodiments, the shaft 700 can be used to connectthe diaphragm 550 to the support member 650. In this manner, the shaft700 can transmit motion from the coil 600 to the diaphragm 550.

As shown in the illustrated embodiment, the first end portion 710 of theshaft 700 can be received within the recess 562 formed in the connectionportion 560 of the diaphragm 560. The end portion 710 can include anundercut portion 712 and an annular lip 714 for securing the shaft 700to the connection portion 560 of the diaphragm 550. The edges of theannular lip 714 can include fillets and/or chamfers similar to those ofthe undercut portion 564 of the recess 562. The end portion 710 can beretained on the connection portion 560 of the diaphragm 550 in aninterference fit. This can beneficially reduce the amount of playbetween the shaft 700 and the connection portion 560 of the diaphragm550. In some embodiments, the shaft 700 can be further secured to theconnection portion 560 of the diaphragm 550 with an adhesive

The intermediate portion 720 can include features for connection to thesupport member 650. For example, as shown in the illustrated embodiment,the intermediate portion 720 can include one or more tapered features722, 724 which can cooperate with the collet 676. The shaft 700 caninclude one or more indexing features, such as longitudinally extendingribs 726, which can cooperate with the indexing features of one or morecomponents of the pump assembly 400, such as the openings 678 of thesupport member 650. In some embodiments, the shaft 700 can be made frommaterials such as plastics, metals, composites, or the like, or acombination of materials. In some embodiments, the shaft 700 can be madefrom polybutylene terephthalate (PBT).

FIG. 38 illustrates a perspective view of an embodiment of a spring 750which can form part of the pump assembly 400. The spring 750 can includean opening 752 through which a component of the pump assembly 400 canpass through, such as the shaft 700. As shown in FIG. 18, the spring 750can be positioned between a platform 728 of the shaft 700 and the collet676 of the support member 650. The spring 750 can include one or moreindexing features, such as cutouts 754, which can correspond to indexingfeatures on the shaft 700 to facilitate alignment and orientation of thespring 750 with respect to the shaft 700. In some embodiments, an outerperiphery of the spring 750 can be positioned between the spacer 590 andthe bushing 800. Accordingly, as the shaft 700 is moved relative to thebushing 800, the force applied to the shaft 700 by the spring 750 canvary. In some embodiments, the spring 750 can include one or morecutouts 758 to allow deformation of the middle portion of the spring 750relative to an outer periphery of the spring 750. The length and widthof these cutouts 758 can be changed to alter the spring constant of thespring 750. In some embodiments, the width of the cutouts can be chosento avoid potential interference between portions of the spring 750during operation of the pump assembly 400.

In some embodiments, the spring member 750 can be sized and designed toprovide frequency tuning or adjustment to the resonance frequency of thediaphragm 550 and/or other oscillating components pump assembly 400. Insome embodiments, the spring member 750 can be designed to help maintainthe radial alignment of the diaphragm 550, coil 600, support member 650,and/or shaft 700 with the remainder of the pump assembly 400. In someembodiments, the spring can provide both functions. The spring member750 can be made from stainless steel such as AISI 301 H03 ¾hard—stainless steel, spring steel, bronze, or any other suitablematerial.

FIGS. 39-40 are various views of an embodiment of a bushing 800 whichcan form part of the pump assembly 400. The bushing 800 can be designedto help maintain the radial alignment of the diaphragm 550, coil 600,support member 650, and/or shaft 700 with the remainder of the pumpassembly 400. The bushing 800 can also be used to limit the movement ofcomponents of the pump assembly 400, such as the support member 650, toavoid damage to other components of the pump assembly 400, such as thediaphragm 550.

As shown in the illustrated embodiment, the bushing 800 can include abase 802 which can extend in a direction generally radially outward froman axial centerline of the bushing 800. The base 802 can include one ormore wall members 804 which can extend generally transverse to the base802. In the illustrated embodiment, the one or more wall members 804extend in a direction generally parallel with the axial centerline ofthe bushing 800. For example, as shown in FIG. 39, the base 802 can havethree wall members 804. The wall members 804 of bushing 800 can bedesigned to push the spring 750 and the spacer 590 against theperipheral portion 570 of the diaphragm 550 such that the lip 574 of thediaphragm 550 is compressed against the pump chamber body 470. Asdiscussed above, compressing the lip 574 of the diaphragm 550 againstthe pump chamber body 470 can improve the sealability of the diaphragm550. For example, in some embodiments, compressing the lip 574 againstthe pump chamber body 470 can help seal the diaphragm chamber 472. Thebase 802 can include a protrusion 806 extending from a surface 808 ofthe base 802. The protrusion 806 can be generally centered on the base802 and can be designed to serve as a stop for the support member 650 asshown more clearly in FIG. 18. For example, the protrusion 806 cancontact the support member 650 at top dead center (“TDC”) for the pumpassembly. In this manner, the support member 650 can be prevented fromover-extending the diaphragm 550 thereby reducing the likelihood ofdamage to the diaphragm 550. As will be described in further detailbelow, the pump chamber body 470 and the bushing 800 can be designed sothat they can be laser welded together. In this way, the bushing 800 andthe pump chamber body 470 are designed so that they do not move withrespect to the oscillating components of the pump, such as for example,the shaft 700, the support member 650, and the diaphragm 550.

In some embodiments, the radial dimension of the protrusion 806, asmeasured from the axial centerline of the bushing 800, can be less thanthe radial dimension of the base 802, such as less than about 75% of theradial dimension of the base 802, less than about 50% of the radialdimension of the base 802, less than about 25% of the radial dimensionof the base 802, between about 25% to about 75% the radial dimension ofthe base 802, between about 40% to about 60% of the radial dimension ofthe base 802, about 50% of the radial dimension of the base, anysubrange within these ranges, or any other percentage as desired. Insome embodiments, the depth of the protrusion 806 relative to the base802 in addition to the radial dimension of the protrusion 806 relativeto the base 802 can be chosen to account for flex in the arms 672 of thesupport portion 650 such that the arms 672 do not contact the base 802during operation of the pump assembly 400.

As shown in the illustrated embodiment, the bushing 800 can includeindexing features, such as the illustrated fingers 810 and ribs 812,which can facilitate in orienting and aligning the bushing 800 withrespect to other components in the pump assembly 400. Moreover, thefingers 810 and ribs 812 can be used to maintain radial alignment of thebushing 800 with respect to other components of the pump assembly 400.In some embodiments, the bushing 800 can include an opening 814 forreceiving a component therein, such as a second end portion 730 of theshaft 700. The opening 814 can be formed through an axial centerline ofthe bushing 800. The diameter of the opening 814 can be designed toreduce wobble in the shaft 700 without applying a significant degree offriction to the shaft 700. The bushing 800 can be formed from a lowfriction material (polymeric or otherwise) or any other suitablematerial. For example the bushing 800 can be made from polycarbonate,phosphor bronze, oilite, PTFE, acetal, nylon, PTFE, or the like, or acombination of materials.

In some embodiments, the bushing 800 can be laser welded to the pumpchamber body 470. For example, as discussed above with respect to laserwelding the pump housing 420 to the pump chamber body 470, a laser beamcan be used to weld an absorber material of the pump chamber body 470 toa transparent material of the bushing 800 by heating up the absorbermaterial to its melting point after passing through the transparentmaterial. The transparent material can allow the laser to pass throughthe bushing and heat the absorber material on and/or within the pumpchamber body. Similarly, the absorber material can include any suitablelaser absorbing pigment that facilitates the absorption of light fromthe laser such that the temperature of the absorber material can beincreased to its melting point. Whereas the transparent material canallow the laser to pass through, the absorber material can allow thelaser to be absorbed. To facilitate absorption of energy from the laser,and to in turn increase the temperature of the absorber material to itsmelting point, the absorber material can include a pigment that absorbsthe wavelength(s) of light emitted by the laser. In some embodiments,the pigment of the absorber material can be darker relative to thetransparent material. For example, in some embodiments, the absorbermaterial can have a well-defined percentage of black pigment, such as,for example, between 1%-10% black pigment, between 1%-100% blackpigment, between 5%-100% black pigment, between 50%-100% black pigment,between 80%-100% black pigment, between 90%-100% black pigment, orbetween any other suitable percentages, or less than 100% black pigment,less than 90% black pigment, less than 50% black pigment, less than 15%black pigment, or less than any other suitable percentage. For example,in some embodiments, the percentage of black pigment in the absorbermaterial can be 1%, 30%, 80%, 95%, 100%, or any other suitablepercentage. In some embodiments, the higher the percentage of laserabsorbing pigment that the absorber material has, the faster theabsorber material will melt for any given laser intensity. In someembodiments, only the portion of the pump chamber body 470 that is to bewelded to the bushing 800 is black. For example, as shown in FIGS. 25and 27, the pump chamber body 470 can include three vertical flanges 485each having a mechanical stop 483 and two circumferential weld surfaces484. In some embodiments, only the weld surfaces 484 are black. Themechanical stops 483 can be designed to control the penetration of thebushing 800 into the pump chamber body 470 during welding. As shown inFIGS. 25 and 27, the three vertical flanges 485 can be separated by thethree slots 482 described above with reference to spacer 590. In someembodiments, the bushing 800 can have three ribs 812. The ribs 812 canadvantageously function to stop penetration of the bushing 800 into thepump chamber body 470 during welding at the desired amount ofpenetration. For example, the ribs 812 can be designed such that abottom surface comes into contact with the mechanical stops 483 of thepump chamber body 470. In this way, the extent of the bushing 800penetration can be controlled.

During the welding process, the pump chamber body 470 and the bushing800 can be held together with a constant, increasing, or decreasingpressure to prevent the two components from moving in any dimensionrelative to one another using, for example, a clamp. For example, insome embodiments, a spring clamp or an air-operated clamp can be used,although any suitable tension providing clamp is envisioned. While thepump chamber body 470 and the bushing 800 are held together, a laserbeam can be guided along a designed melt contour. For example, in someembodiments, the pump chamber body 470 can have a laser absorbingpigment along the melt contour. The resultant melt contour representsthe laser weld between the pump chamber body 470 and the bushing 800. Insome embodiments, the melt contour 890 that connects the pump chamberbody and the bushing together can be designed as shown in FIG. 59. Ofcourse, any other suitably shaped contour congruent with a weld surface484 of the vertical flange 485 is envisioned. Once the melt contoursolidifies, a strong connection between the pump chamber body 470 andbushing 800 is created. In some embodiments, the transparent andabsorbent materials can be chosen such that they are chemicallycompatible. For example, the transparent and absorbent materials can bedifferent pigments of the same molecules. With reference to FIG. 19, thepump chamber body 470 can be laser welded to the bushing from thetopside of the bushing 800.

FIGS. 41-46 illustrate embodiments of noise reduction systems. As shownin the illustrated embodiment in FIG. 41, the noise reduction system caninclude a chamber 430 formed integrally with the pump housing 420. Forexample, in some embodiments, the chamber 430 can be integrally formedwith the pump housing 420 as shown FIG. 42, which is a sidecross-sectional view of the pump housing of FIG. 41 along line AA. FIGS.21 and 22 also show embodiments having a chamber 430 integrally formedwith a pump housing 420. Of course, the chamber 430 shown in FIGS. 41,42, 21, and 22 is exemplary and non-limiting and the skilled artisanwill appreciate that any other suitable integrally formed chamber isenvisioned. In some embodiments, the chamber 430 can be separate fromthe pump housing 420 and can be attached to the pump housing 420. Forexample, FIGS. 44 and 45 show a pump housing 420′, 420″ in which thechamber 430 has been separated from the pump housing 420′, 420″. It willbe appreciated that the chamber 430 can be attached to the pump housing420 in FIGS. 44 and 45 at any suitable location along the fluid flowpath, such as, for example, somewhere along the exhaust channel 424′ inFIG. 44 or somewhere around the opening 436″ in FIG. 45.

The chamber 430 can be designed to receive a dampening component 902(also referred to as a silencer). The dampening component can reducenoise emissions from the pump. For example, in some embodiments, theouttake flow of the pump can be passed through the dampening componentsuch that frequencies and/or amplitudes of the pressure waves in theouttake flow are reduced, which in turn dampens the noise emitted by thepump. The dampening component 902 can be integrated into a pump housingby being placed in the pump chamber 430. As described above, in someembodiments, the pump chamber 430 can be integrally formed with the pumphousing 420, and in other embodiments, the pump chamber 430 can beseparately attached to the pump housing 420′. For example, as shown inFIGS. 41, 42, 21, and 22, the dampening component 902 can be integratedwith the pump housing 420 by being placed within the chamber 430. Inother embodiments, the dampening component can be placed within achamber 430 that is separately attached to the pump housing 420. Asshown in the illustrated embodiments, the dampening component 902 can bereceived within (also referred to as integrated with) the chamber 430 ina friction and/or interference fit, although any suitable connectionbetween the dampening component 902 and the chamber 430 is appreciatedand envisioned. In some embodiments, the dampening component 902 can beprevented from exiting the chamber 430 via one or more features of theouter housing 102. In some embodiments, the orientation of the chamber430 shown in FIGS. 41, 42, 21, and 22 can be flipped as is shown in FIG.47 which illustrates a pump housing 420′″ and chamber 430′″. In someembodiments, the chamber 430′″ can be integrally formed with the pumphousing 420′. In addition, as discussed above with reference to FIG. 22and other related figures, in some embodiments, the exhaust channel 422can channel or communicate fluid towards an exhaust port 428 and into aninterior of a chamber 430 where it can eventually be exhausted into theatmosphere within the outer housing 102 after being channeled orcommunicated through a silencer 902.

The dampening component 902 can be made from any material capable ofallowing fluid passage, such as air, through the dampening component 902while reducing noise. For example, in some embodiments, the dampeningcomponent 902 can be formed from a porous material such as foam,including but not limited to urethane foam, which can advantageouslyallow fluid flow through the foam while reducing noise generated. Insome embodiments, the material of the dampening component 902 can bemedical grade. The thickness of the dampening component 902 can bechosen based on numerous factors including the type of material used,the desired fluid flow out of the dampening component 902, and theamount of noise reduction desired. In some embodiments, the dampeningcomponent 902 can also serve as a filter which can reduce undesirablecomponents in the fluid as the fluid flows through the dampeningcomponent 902. For example, in some embodiments, the dampening componentcan be a foam insert 3 millimeters thick. The skilled artisan willappreciate that the foam insert can take on any suitable shape capableof fitting into the chamber 430, such as, for example, cylindrical orpolygonal. Of course, other shapes and sizes are also envisioned. Forexample, in some embodiments, the foam insert can range in thicknessfrom approximately 1 millimeter to approximately 5 millimeters.

As shown in the illustrated embodiment, the chamber 430 can include oneor more ribs 431 extending from an inner surface 433 of the chamber 430.The ribs 431 can beneficially space the dampening component 902 from theinner surface 433 such that a gap is formed between the dampeningcomponent 902 and the inner surface 433. This gap can allow for fluidflow from the exhaust port 428 to expand into the gap prior to flowingthrough the dampening component 902. This can beneficially reduce thelikelihood of choking the exhaust flow. In some embodiments, the exhaustport 428 can be designed to have a diffuser 437 shape similar to thatillustrated in FIG. 43 to further control expansion of the fluid as thefluid passes through the exhaust port 428 and into the chamber 430.

In some embodiments, the noise reduction system can involve redirectingat least some portion of the exhaust gases back into the pump housing420. For example, as shown in FIG. 44, a pump housing 420′ can includean opening 436′ positioned along the exhaust channel 424′ forredirecting at least some of the exhaust flow back into an internalvolume of the pump housing. This can separate flow between the channel424′ and the internal volume of a pump assembly where the sound-waveencounters different geometries and may thereby be dampened. In someembodiments, such as that illustrated in FIG. 45, the entirety of theexhaust flow can be directed back into the internal volume of the pumphousing 420″ via opening 436″.

With reference to FIG. 46, in some embodiments, a manifold 300′ of thepump system 100 can incorporate noise reducing features. For example, asshown in the illustrated embodiment, the manifold 300′ can include aninlet passageway 310′ having an inlet opening 312′ designed to be influid communication with a wound dressing and an outlet opening 314′which can be in fluid communication with an intake of the pump assembly,such as intake port 426 of the pump housing 420. The inlet passageway310′ can include one or more additional ports, such as port 316′,designed to be in fluid communication with other components of the pumpsystem 100, such as the pressure monitor 204. The manifold 300′ caninclude an outlet passageway 318′ having an inlet opening 320′ designedto be in fluid communication with an exhaust of the pump assembly, suchas exhaust port 428 of the pump housing 420, and an outlet opening 322′designed to exhaust the fluid into the atmosphere such as within theouter housing 102. In some embodiments, the manifold 300′ can be used toattenuate the noise produced by the pump assembly. For example, theinlet passageway 310′ and/or the outlet passageway 318′ can be designedto receive a dampening component 902′ to reduce noise generated by thepump assembly. In some embodiments, the dampening component 902′ can beused to help stabilize the air volume in the manifold so that thepressure monitor 204 can return more accurate readings. For example, insome embodiments, the dampening component 902′ can be used to attenuatethe noise generated from the harmonic dynamics (also referred to as theresonance) of the pump. In some embodiments, the inlet opening 312′, theoutlet opening 314′, the inlet opening 320′, and/or the outlet opening322′ can be designed to have a diffuser shape and/or nozzle shape tohelp control the expansion or compression of fluid. In some embodiments,the manifold can have an internal volume of approximately 870 mm³.

With reference back to FIGS. 14-16, in some embodiments, the pumpassembly 400 can have one or more dampening components 904 attached to asurface of the device. The dampening components 904 can be designed toreduce noise and/or vibration generated by movement of the pump assembly400 within the outer housing 102. In some embodiments, one or moredampening components 904 can be attached to the front and rear surfacesof the pump assembly 400. For example, as shown in FIGS. 14-16, the pumpassembly 400 can have six dampening components 904, three on a rear sideof the pump assembly as shown in FIG. 15, and three on a front side ofthe pump assembly as shown in FIGS. 14 and 16. Advantageously, the oneor more dampening components 904 can be used to decouple and/or cushionthe pump assembly 400 from one or more of the hard components thatsurround the pump assembly and/or from the main circuit board of thepump system. For example, in some embodiments, the one or more dampeningcomponents 904 on the front side of the pump assembly 400 can bedesigned to be placed between the front side of the pump assembly andthe circuit board 200 (shown in FIG. 13), and the one or more dampeningcomponents 904 on the rear side of the pump assembly 400 can be designedto be placed between the rear side of the pump assembly and the rearportion of the outer housing 102 b (shown in FIG. 11). In someembodiments, the dampening components 904 can be made from any materialhaving noise and/or vibration dampening characteristics such as foam.For example, the one or more dampening components can be foam cylinders,although any suitable shape is envisioned. In some embodiments, a layerof open foam or other material can be wrapped at least partially aroundan outside surface of the pump assembly 400 to reduce noise and/orvibration produced by the pump assembly 400. Additionally, in someembodiments, the pump assembly 400 can have one or more weights,cushions, foam (such as a viscoelastic foam), plastic (such as ABS,polyurethane, urethane, or otherwise), or other pads, panels, sheets, orsegments supported by the pump or positioned adjacent to one or moreoutside surfaces of the pump. In some embodiments, the pump assembly 400can have mass based or compliant damping materials. Such components ormaterials (not illustrated) can damp vibration and/or attenuate noiseproduced by the pump.

FIGS. 48-49 are various views illustrating wiring of the pump system 100within the outer housing 102. As shown in the illustrated embodiment,the pump system 100 can include terminals 210 for connecting the circuitboard 200 to a power source, such as batteries 202. The circuit board200 can route power from the power source to the coil 600 via anelectrical conduit 604 attached to a connector 212 of the circuit board200. In some embodiments, the electrical conduit 604 can be a flexibleprinted circuit (FPC) to facilitate assembly. In some embodiments, theelectrical conduit 604 can be connected directly to the coil 600. Forexample, the ends of the FPC corresponding to a positive and negativeterminal can be attached, such as via soldering and/or via adhesives, toends or terminals of the coil 600. For example, the coil 600 can havetwo terminals that can be soldered to two corresponding solder pads ofthe FPC. However, the wire used to manufacture the coil can be protectedby an insulation layer and a self-bonding coating layer that can makemanual soldering difficult and/or unreliable since manual soldering canexpose the FPC to temperatures of 400 degrees Celsius for too long atime, which can damage the FPC substrate. To mitigate this problem, insome embodiments, a micro welding process can be used to electricallyconnect the FPC to the two terminals of the coil 600. In micro welding,a high current spike can be generated for a few milliseconds between theterminals of the coil and the pads of the FPC. The current spike canresult in a localized temperature spike that can vaporize the insulatingand self-bonding layers of the wire so that the wire of the coil can bebonded to the pads of the FPC. For example, the temperature spike can be400 degrees Celsius or higher. However, since the temperature spike islimited to a few milliseconds using the micro welding process, the FPCsubstrate is not damaged.

FIG. 50 illustrates an embodiment of a coil 600′ and a support member650′. The support member 650′ can incorporate electrically conductivepins 651′ which can connect terminals of the coil 600′ to a powersource, such as control board 200. As shown in the illustratedembodiment, the terminals of the coil 600′ can be attached to the pins651′ via soldering and/or adhesives.

FIG. 51 illustrates one example of a connection mechanism for connectingthe coil 600 to the power source. As shown in the illustratedembodiment, the pins 651′ can extend past the pump chamber body 470′ andinto contact with a leaf spring 214′. The leaf spring 214′ can beconnected to terminal ends of an electrical conduit 604′ for a powersource, such as terminal ends of an FPC. Accordingly, as the supportmember 650″ moves in the vertical direction, the leaf spring 214′ canmaintain contact with the pins 651′.

FIG. 52 illustrates another example of a connection mechanism forconnecting coil 600′ to the power source. As shown in the illustratedembodiment, an electrically conductive coil spring 215′ can extend intothe pump chamber body 470′ and into contact with one or more terminalsof the coil 600′. Accordingly, as the coil 600′ moves in the verticaldirection, the coil spring 215′ can compress and/or expand. In someembodiments, the electrically conductive coil spring 215′ can be incontact with pins (not shown) on the support member 650′. The coilspring 215′ can be connected to terminal ends of an electrical conduitfor a power source, such as terminal ends of an FPC.

FIG. 53 illustrates another example of a connection mechanism forconnecting coil 600′ to the power source. As shown in the illustratedembodiment, an electrically conductive zebra connector 218′ can extendinto the pump chamber body 470′ and into contact with one or moreterminals of the coil 600′. Accordingly, as the coil 600′ moves in thevertical direction, the zebra connector 218′ can maintain contact withterminals of the coil 600′. In some embodiments, the zebra connector218′ can be in contact with pins (not shown) on the support member 650′.The zebra connector 218′ can be connected to terminal ends of anelectrical conduit for a power source, such as terminal ends of an FPC,or contacts 219′.

FIG. 54 illustrates another example of a connection mechanism forconnecting coil 600′ to the power source. As shown in the illustratedembodiment, one or more individual terminals of the coil 600′ can beencased together in a membrane 220′ which extends out of pump chamberbody 470′. The membrane 220′ can be made from any suitable material,such as silicone. The individual terminals can then be attached, viasoldering and/or adhesives, to more robust wiring 222′ for routingtowards the power source.

FIG. 55 illustrates another example of a connection mechanism forconnecting coil 600′ to the power source. As shown in the illustratedembodiment, the electrical conduit 604′ can be integrated with thespring 750′.

In some embodiments, the pump system 100 can be configured such that thebattery connections or terminals have polarity protection. For exampleand without limitation, one or more of the battery contacts can bedesigned to have plastic or other non-conductive protrusions adjacent tothe battery terminal contacts to inhibit the contact between the batterycontact and the incorrect side of a battery that is inserted into thebattery compartment in the incorrect orientation. In some embodiments,the one or more protrusions can be sized and designed to prevent thenegative side of a standard cylindrical battery from contacting thebattery contact adjacent to the one or more protrusions, whilepermitting a positive side of such battery to contact the batterycontact. Generally, with this configuration, the battery can generallyonly make contact with the contact if the battery is inserted in thebattery compartment in the correct orientation, thereby providingpolarity protection to the pump assembly. Alternatively or additionally,a control board of the pump assembly can be designed to have polarityprotective features or components. Additionally, a control board of thepump assembly can have one or more fuses to protect against overpowerconditions or surge power conditions.

In any of the embodiments disclosed herein, the control board 200 can bea flexible circuit board and/or can have one or more flexiblecomponents. A flexible circuit board is generally a patternedarrangement of printed circuitry and components that utilizes flexiblebased material with or without flexible overlay. These flexibleelectronic assemblies can be fabricated using the same components usedfor rigid printed circuit boards, but allowing the board to conform to adesired shape (flex) during its application. In their simplest form,flexible circuits are PCBs made of materials that allow for a non-planarpositioning within the end product. Typical materials a polyimide-based,and can go under trade names such as Kapton (DuPont). Additionally, anyof the control boards or controllers disclosed herein can have acombination of flexible and rigid substrates laminated into a singlepackage.

Overview of the Electrical Aspects of the Pump System

FIG. 60 illustrates a schematic of an embodiment of a pump system 1000.In some embodiments, the pump system 1000 can have any of the same orsimilar components, features, materials, sizes, configurations, andother details of any other pump system embodiments disclosed orincorporated by reference herein, including the embodiment of the pumpsystem 100 described above. In some embodiments, the pump system 1000can be miniaturized and portable, although larger conventional portableor non-portable (e.g., wall suction) pumps can also be used.

As shown in the illustrated embodiment, the pump system 1000 can includea switch or a button 1002, one or more indicators 1004, and a controlboard 1006. The button 1002 and/or the one or more indicators 1004 canbe in electrical communication with the control board 1006. As isexplained in further detail below, in some embodiments the button 1002can be used for any suitable purpose for controlling an operation of thepump system 1000. For example, button 1002 can be used to activate thepump system 1000, pause the pump system 1000, clear system indicators1004, and/or be used for any other suitable purpose for controlling anoperation of the pump system 1000. Button 1002 can by any type of switchor button, such as a touchpad, touch screen, keyboard, and so on. Insome embodiments, the button 1002 can be a press button. For example,the button 1002 can be similar to button 116 of pump system 100.

In some embodiments, the one or more indicators 1004 can indicate one ormore operating and/or failure conditions of the pump system 1000. Insome embodiments, each of the one or more indicators 1004 can provide anindication regarding a different operating and/or failure condition. Forexample, an active (e.g., lit) indicator 1004 can represent normaloperation. Another indicator 1004, for example a dressing indicator, canprovide an indication as to presence of leaks in the system. Forexample, an active (e.g., lit) dressing indicator can represent a leak.Another indicator 1004, for example a dressing capacity indicator, canprovide an indication as to the remaining fluid capacity of a dressing.For example, an active (e.g., lit) dressing capacity indicator canrepresent that the dressing is at or nearing capacity. Another indicator1004, such as a battery indicator, can provide an indication as toremaining capacity or life of a power source, such as batteries. Forexample, an active (e.g., lit) battery indicator can represent a lowcapacity. In some embodiments, an indicator 1004 can represent acombination of the above operating and/or failure conditions of the pumpsystem 1000 and/or other operating and/or failure conditions.

With continued reference to the embodiment of pump system 1000illustrated in FIG. 60, in some embodiments, the one or more indicators1004 can be icons. For example, the one or more indicators 1004 can besimilar to the icons 114 of pump system 1004 and can be activated (e.g.,lit) via an illumination source such as LEDs 206 of pump system 100. Insome embodiments, the one or more indicators 1004 can be of a differentcolor, two different colors (e.g., two indicators can share the samecolor), or the same color. Although the pump system 1000 can includefour icons and a push play/pause button, other configurations,locations, and types of indicators, alarms, and switches canalternatively be used. In some embodiments, the pump system 1000 caninclude visual, audible, tactile, and other types of indicators oralarms configured to signal to the user various operating conditions.Such conditions include system on/off, standby, pause, normal operation,dressing problem, leak, error, and the like. The indicators can includespeakers, displays, light sources, etc., and/or combinations thereof.

As shown in the illustrated embodiment, the pump system 1000 can bepowered by a power source 1008 such as a battery power cell. The pumpsystem 1000 can also include a source of negative pressure 1010, such asa pump assembly having a pump 1012 powered by an electric motor 1014,and a pressure sensor 1016, such as pressure monitor 204 of pump system100. In some embodiments, the pump system 1000 can include an inlet 1018to connect the pump system 1000 to a wound dressing. For example, insome embodiments, the inlet 1018 can be a connector for connecting theinlet 1018 to a conduit which is in fluid communication with a wounddressing. The connector can be similar to connector 302 of pump system100. The pump 1012 can be connected to an outlet 1020. In someembodiments, the outlet 1020 can vent air to the atmosphere. In someembodiments, a filter (not shown) can be interposed between the outletand the atmosphere. The filter can provide filtration of the air priorto venting to the atmosphere. In some embodiments, the filter can be abacterial filter, odor filter, etc. or any combination thereof. In someembodiments, a dampening component (not shown), such as a noisedampening component, can be interposed between the outlet and theatmosphere. The dampening component can reduce the noise generated bythe pump system 1000 during operation. In some embodiments, thedampening component can be similar to dampening component 902 of pumpsystem 100.

In some embodiments, the pump system 1000 can include a valve (notshown), such as a one-way valve, in a flow passage between the wounddressing and an inlet of the pump 1012. The valve can help maintain alevel of negative pressure when the pump 1012 is not active. In someembodiments, the valve can help avoid leaks. The valve can also helpprevent fluids and/or exudate aspirated or removed from the wound fromentering the pump system 1000.

FIG. 61 illustrates an electrical component schematic of a pump system1100 according to an embodiment. In some embodiments, the pump system1100 can have any of the same or similar components, features,materials, sizes, configurations, and other details of any other pumpsystem embodiments disclosed or incorporated by reference herein,including the embodiment of the pump system 100, 1000 described above.Pump system 1100 can include one or more buttons 1102, one or moreindicators 1104, one or more pressure sensors 1106, power source 1108, asource of negative pressure 1109, and/or a module 1110. In someembodiments, the one or more buttons 1102, one or more indicators 1104,one or more pressure sensors 1106, power source 1108, and/or source ofnegative pressure 1109 can be similar to button 1002, indicators 1004,pressure sensor 1016, power source 1008, and/or source of negativepressure 1010 of pump system 1000. Module 1110, which can be a controlboard (e.g., PCBA), can include an input/output (110) module 1112,controller 1114, and memory 1116. In some embodiments, module 1110 caninclude additional electric/electronic components, for example, fuse orfuses, or external memory (such as flash-memory). The controller 1114can be a microcontroller, processor, microprocessor, etc. or anycombination thereof. For example, the controller 1114 can be of theSTM8L MCU family type from ST Microelectronics, such as STM8L 151G4U6 orSTM8L 151K6U6TR, or of MC9S08QE4/8 series type from Freescale, such asMC9S08QE4CWJ. Preferably, the controller 1114 is a low power or ultralow power device, but other types of devices can alternatively be used.Memory 1116 can include one or more of volatile and/or nonvolatilememory modules, such as one or more of read-only memory (ROM), writeonce read many memory (WORM), random access memory (e.g., SRAM, DRAM.SDRAM, DDR, etc.), solid-state memory, flash memory, Magnetoresistiverandom-access memory (MRAM), magnetic storage, etc. or any combinationthereof. Memory 1116 can be configured to store program code orinstructions (executed by the controller), system parameters,operational data, user data, etc. or any combination thereof. In someembodiments, one or more components of the pump system 1100 can formpart of a monolithic unit. In some embodiments, the memory 1116 can be16 megabits, 32 megabits, or of another suitable size depending on theamount of data configured to be logged during operation of the pumpsystem 1100. In some embodiments, the logged data can be stored toadvantageously gather information that is relevant to clinical trial(s).In some embodiments, one or more components of the pump system 1100 canbe removable from other components. For example, in some embodiments,memory 1116 can be removable flash memory.

FIG. 62 illustrates an electrical component schematic of a pump system1200 according to an embodiment. In some embodiments, the pump system1200 can have any of the same or similar components, features,materials, sizes, configurations, and other details of any other pumpsystem embodiments disclosed or incorporated by reference herein,including the embodiment of the pump system 100, 1000, 1100 describedabove. Electrical components can operate to accept user input, provideoutput to the user, operate the pump system and the source of negativepressure, provide network connectivity, and so on. Electrical componentscan be mounted on one or more PCBs (not shown). The pump system caninclude a controller or processor 1202. In any embodiments disclosedherein, the controller 1202 can be a general purpose processor, such asa low-power processor. In other embodiments, the controller 1202 can bean application specific processor. In any embodiments disclosed herein,the controller 1202 can be configured as a “central” processor in theelectronic architecture of the pump system, and the controller 1202 cancoordinate the activity of other controllers, such as a user interfacecontroller 1204, I/O interface controller 1206, negative pressurecontrol module 1208, communications interface controller 1210, and thelike.

The pump system 1200 can also include a user interface controller orprocessor 1204 which can operate one or more components for acceptinguser input and providing output to the user, such as buttons, indicators(e.g., LEDs), displays, etc. Input to the pump system 1200 and outputfrom the pump system 1200 can be controlled via one or more input/output(I/O) ports 1212 controlled by a I/O interface module or controller1206. For example, the I/O module 1206 can receive data from one or moreI/O ports 1212, such as serial, parallel, hybrid ports, expansion ports,and the like. In any embodiments disclosed herein, I/O ports 1212include one or more of USB ports, SD ports, Compact Disc (CD) drives,DVD drives, FireWire ports, Thunderbolt ports, PCI Express ports, andthe like. The controller 1202, along with other controller orprocessors, can store data in one or more memory modules 1214, which canbe internal and/or external to the system 1200. Any suitable type ofmemory can be used, including volatile and/or non-volatile memory, suchas RAM, ROM, WORM, magnetic memory, solid-state memory, MRAM, and thelike or any combination thereof. The pump system 1200 can be powered bya power source 1216, which can comprise one or more disposable orrechargeable batteries, power from mains, etc. The power source 1216 canbe internal or external to the system 1200.

With continued reference to the embodiment of pump system 1200illustrated in FIG. 62, in some embodiments, a negative pressure or pumpcontrol module 1208 can be configured to control the operation of anegative pressure source 1218. The negative pressure source 1218 can bea voice coil pump. Other suitable pumps include diaphragm pumps,peristaltic pumps, rotary pumps, rotary vane pumps, scroll pumps, screwpumps, liquid ring pumps, diaphragm pumps operated by a piezoelectrictransducer, and the like. The pump control module 1208 can include adriver module 1220 configured to control the operation of the negativepressure source 1218. For example, the driver module 1220 can providepower to the negative pressure source 1218. Power can be provided in aform of a voltage and/or current signal. In any embodiments disclosedherein, the driver module 1220 can control the negative pressure source1218 using pulse-width modulation (PWM). A control signal for drivingthe negative pressure source 1218 (or pump drive signal) can be a 0-100%duty cycle PWM signal. The drive module 1220 can control the negativepressure source 1218 using any other suitable control, such asproportional-integral-derivative (PID).

The controller 1202 can receive information from one or more sensors,such as pressure sensors 1206, placed in a suitable location in a fluidflow path, such as pressure monitor 204 placed within intake manifold300 of pump system 100. In any embodiments disclosed herein, thecontroller 1202 can measure pressure in the fluid flow path, using datareceived from one or more pressure sensors 1206, calculate the rate offluid flow, and control the negative pressure source 1218 so thatdesired level of negative pressure is achieved in a wound cavity orunder the dressing. The desired level of negative pressure can bepressure set or selected by a user. Pressure measured by the one or moresensors can be provided to the controller 1202 so that the controllercan determine and adjust the pump drive signal to achieve the desirednegative pressure level. In any embodiments disclosed herein, the tasksassociated with controlling the negative pressure source 1218 can beoffloaded to the pump control module 1208, which can include one or morecontrollers or processors.

In any embodiments disclosed herein, it may be advantageous to utilizemultiple processors for performing various tasks. In any embodimentsdisclosed herein, a first processor can be responsible for user activityand a second processor can be responsible for controlling the negativepressure source. This way, the activity of controlling the negativepressure source, which may necessitate a higher level of responsiveness,can be offloaded to a dedicated processor and, thereby, will not beinterrupted by user interface tasks, which may take longer to completebecause of interactions with the user.

A communications interface controller or processor 1210 can beconfigured to provide wired and/or wireless connectivity. Thecommunications processor 1210 can utilize one or more antennas (notshown) for sending and receiving data. In any embodiments disclosedherein, the communications processor 1210 can provide one or more of thefollowing types of connections: Global Positioning System (GPS)technology, cellular or other connectivity, such as 2G, 3G, LTE, 4G,WiFi, Internet connectivity, Bluetooth, zigbee, RFID, and the like.Additionally, any embodiments disclosed herein can be configured tosynchronize, upload, or download data to and/or from the pump apparatusto and/or from a portable data device, such as a tablet, smart phone, orother similar devices.

Connectivity can be used for various activities, such as pump systemlocation tracking, asset tracking, compliance monitoring, remoteselection, uploading of logs, alarms, and other operational data, andadjustment of therapy settings, upgrading of software and/or firmware,and the like. In any embodiments disclosed herein, the communicationsprocessor 1210 can provide dual GPS/cellular functionality. Cellularfunctionality can, for example, be 3G and/or 4G functionality. In suchcases, if the GPS module is not be able to establish satelliteconnection due to various factors including atmospheric conditions,building or terrain interference, satellite geometry, and so on, thedevice location can be determined using the 3G and/or 4G networkconnection, such as by using cell identification, triangulation, forwardlink timing, and the like. In any embodiments disclosed herein, the pumpsystem 1200 can include a SIM card, and SIM-based positional informationcan be obtained.

Pump System Control

FIG. 63 illustrates a top level state diagram 1300 of operation of thepump system according to some embodiments. In some embodiments, the pumpsystem, such as pump systems 100, 1000, 1100, 1200 and any otherembodiments disclosed herein, can control the operation of the system.For example, the pump system can provide a suitable balance betweenuninterrupted delivery of therapy and/or avoidance of inconveniencingthe user by, for example, frequently or needlessly pausing or suspendingtherapy and a desire to conserve power, limit noise and vibrationgenerated by the negative pressure source, etc. In some embodiments, thecontroller, such as controllers 1114, 1202, can be configured toimplement the flow of the state diagram 1300. As is illustrated in FIG.63, the operation of the pump system can, in some embodiments, begrouped into three general modes: initialization 1302, operational 1310,which includes maintenance 1350, and end of life 1390. As is illustratedin FIG. 63, categories 1302, 1310, and 1350 can each include multiplestates and transitions between states.

In some embodiments, so long as a power source is not connected orremoved, or the pump system has not been activated (e.g., by pulling anactivation strip, triggering the switch, or the like), the pump systemcan remain in an inactive state. While remaining in this state, the pumpsystem can remain inactive. When the power source is connected and/orthe pump system has been activated from the inactive state, such asbeing activated for the first time, the pump system can transition to aninitialization mode 1302, where a bootloader 1301 can initiate asequence of startup procedures as shown in block 1304. The bootloader1301 can be stored on any suitable non-volatile memory such as, forexample, read only memory (ROM), erasable programmable read only memory(EPROM), electrically erasable programmable read-only memory (EEPROM),and the like. In some embodiments, controllers 1114 or 1202 can executethe bootloader 1301 upon startup. The startup procedures can includepower on selftest(s) (POST) and other tests or procedures that can beperformed as shown in startup block 1304. As shown in FIG. 63, thebootloader 1301 can initiate one or more of the POST(s) and/or one ormore of the other tests. In some embodiments, the startup procedures canadvantageously prepare and/or ensure that the pump system will delivernegative pressure wound therapy safely during operation.

Power on self test(s) can include performing various checks to ensureproper functionality of the system, such as testing one or morecomponents of the system including, but not limited to, memory such asmemory 1116, 1214 (e.g., performing a check, such as a cyclic redundancycheck (CRC check), of the program code to determine its integrity,testing the random access memory, etc.), reading the pressure sensorsuch as pressure sensors or monitors 204, 1016, 1106, 1206, to determinewhether the pressure values are within suitable limits, reading theremaining capacity or life of the power source (e.g., battery voltage,current, etc.) to determine whether it is within suitable limits,testing the negative pressure source, and the like. Other tests orprocedures can include waiting for automatic test equipment (ATE),initializing a watch dog timer (WDT), checking whether the pump systemhas previously entered a non-recoverable error (NRE), and determiningwhether the pump system has reached the end of its allotted operationallifespan (also referred to as its end of life (EOL)), and the like. Forexample, in some embodiments, the WDT can advantageously be used as acountermeasure to a firmware execution hanging conditions, the check fora previous NRE can advantageously prevent the reuse of a device that hastransitioned to an NRE state, and the check of whether the device hasreached its end of life can advantageously prevent the reuse of a devicethat has transitioned to an EOL state.

In some embodiments, the bootloader 1301, which can be executed by thecontrollers 1114, 1202, can also initiate the operational mode 1310. Forexample, as shown in FIG. 63, the bootloader can execute initializationof the operational mode 1310 after the initialization mode 1302 has beenperformed. In some embodiments, one or more indicators (such as icons114, 114′ and/or indicators 1004, 1104) can indicate to the user (e.g.,by blinking or flashing once) that the pump system is undergoing POSTtest(s). In some embodiments, during the initialization mode 1302, allindicators can continuously remain on.

In some embodiments, the one or more indicators can blink or flashintermittently or continuously to indicate to the user that the systemhas passed the POST(s) and/or other tests and procedures. For example,as discussed above with reference to FIG. 56, in some embodiments, theone or more indicators can include a set of four icons 114′ that includean “OK” indicator which can indicate normal operation of the pump system100, a “leak” indicator which can indicate the existence of a leak inthe pump system 100 or components attached thereto, a “dressing full”indicator which can indicate that a wound dressing is at or nearcapacity, and a “battery critical” indicator which can indicate that thebattery is at or near a critical level. In some embodiments, the one ormore indicators can be individually or cooperatively illuminated toindicate to the user that the pump system has passed POST(s) and/orother tests and procedures. For example, in some embodiments, the set offour icons 114′ can be cooperatively illuminated to indicate that thesystem has passed the one or more tests such that the “OK” LED flashesonce, the “leak” LED flashes once, the “dressing full” LED flashes once,and the “battery critical” LED flashes once. Similarly, if a previousnon-recoverable error is discovered during startup or subsequentlyencountered during pump operation, the set of four icons 114′ can becooperatively illuminated such that the “OK” LED is solid, the “leak”LED is solid, the “dressing full” LED is solid, and the “batterycritical” LED is solid. Any suitable individual or cooperative LEDarrangement is envisioned in certain embodiments. In variousembodiments, in addition to or instead of providing the visualindication using the one or more indicators, other indications can beprovided, including audible, tactile, and the like.

In some embodiments, if one or more of the POST test(s) or other testsor procedures fail, the pump system can transition to a retry state1306. The retry state 1306 can include a delay and/or require user inputbefore retrying the POST test(s) or other tests or procedures. In someembodiments, the retry state 1306 can be executed until each test orprocedure that is part of the initialization mode passes or otherwisedoes not fail. In some embodiments, if one or more of POST test(s) failafter one or more retries, the pump system can transition to anon-recoverable error state. While in this state, the pump system candeactivate therapy, and indicators can indicate to the user that anerror was encountered. In some embodiments, all indicators can remainactive. Based on the severity of error, in some embodiments, the pumpsystem can recover from the error and continue operation (or transitionto the non-recoverable error state 1394). As is illustrated, the pumpsystem can transition to the non-recoverable error state 1394 uponencountering a fatal error during operation. Fatal errors can includeprogram memory errors, program code errors (e.g., encountering aninvalid variable value), controller operation errors (e.g., watchdogtimer expires without being reset by the controller such as controller1114, 1202), component failure (e.g., inoperative negative pressuresource such as negative pressure sources 1010, 1109, 1218, inoperativepressure sensor such as pressure sensors or monitors 204, 1016, 1106,1206, etc.), and any combination thereof.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, when initialization has been successfullycompleted in state 1304, the pump system can transition to theoperational mode 1310. This transition can be indicated to the user bydeactivating and/or activating one or more indicators. In someembodiments, when the pump system transitions into the operational mode1310, the pump system can first enter a standby or paused state 1312.While the pump system remains in the standby state 1312, the user can beprovided an indication, such as by deactivating and/or activatingindicators (e.g., an OK indicator and/or a dressing indicator). In someembodiments, the user can be provided an indication of the standby state1312 by deactivating all indicators. In some embodiments, therapy can besuspended while the pump system remains in the standby state 1312. Forexample, the source of negative pressure such as sources of negativepressure 1010, 1109, 1218, can be deactivated (or turned off). In someembodiments, indication can be provided to the user by deactivating thesource of negative pressure.

In some embodiments, the pump system can be configured to make atransition from the standby state 1312 to an initial pump down (“IPD”)state 1314 (where the pump system is configured to deliver therapy) inresponse to receiving a signal from the user. For example, the user canpress a button to start, suspend, and/or restart therapy. In someembodiments, the pump system can monitor the duration of time the pumpsystem remains in the standby state 1312. This can be accomplished, forexample, by maintaining a timer (in firmware, software, hardware or anycombination thereof), which can be reset and started when the pumpsystem transitions into the standby state 1312. The pump system canautomatically make the transition from the standby state 1312 to the IPDstate 1314 when the time duration exceeds a threshold (e.g., times out).In some embodiments, such threshold can be a preset value, such asbetween 1 minute or less and 1 hour or more. In some embodiments, thethreshold can be set or changed by the user. In some embodiments, thethreshold can be varied based on various operating conditions or on anycombination thereof. For example, as the pump system nears the end oflife (as is explained below), the threshold can be decreased used overthe lifespan of the pump system. This can advantageously ensure that thebattery is used more efficiently over the lifespan of the pump system byreducing the amount of time spent in the standby state 1312 andutilizing more of the battery by activating the pump sooner. In someembodiments, the pump system can monitor the entire amount of time spentin the standby state and store this information in memory.

During the IPD state 1314, the pump system can activate the source ofnegative pressure to begin therapy and reduce pressure in the system orsome portion thereof, such as a fluid flow path between a source ofnegative pressure and a wound dressing. In some embodiments, the pumpsystem can reduce pressure in the system to a desired pressure, such asa low pressure threshold. The pump system can intermittently and/orcontinuously monitor the pressure in the pump system or some portionthereof. For example, the pump system can monitor the pressure in thepump system or some portion thereof at a preset sampling rate ofapproximately 100 ms. In some embodiments, the sampling rate can bebetween approximately 20 ms and approximately 500 ms, betweenapproximately 50 ms and 250 ms, between approximately 80 ms and 150 ms,approximately 100 ms, any value and/or subrange with these ranges, orany other sampling rate as desired. In some embodiments, the pump systemcan also calculate the rate of pressure change to estimate the amount oftime until the pump system reaches a desired pressure, such as the lowpressure threshold.

In some embodiments, one or more indicators can blink or flashintermittently or continuously to indicate to the user that the pumpsystem is in the IPD state. For example, as discussed above withreference to FIG. 56, in some embodiments, the one or more indicatorscan include a set of four icons 114′ that include an “OK” indicatorwhich can indicate normal operation of the pump system 100, a “leak”indicator which can indicate the existence of a leak in the pump system100 or components attached thereto, a “dressing full” indicator whichcan indicate that a wound dressing is at or near capacity, and a“battery critical” indicator which can indicate that the battery is ator near a critical level. In some embodiments, the one or moreindicators can be individually or cooperatively illuminated to indicateto the user that the system is in the IPD state. For example, in someembodiments, the set of four icons 114′ can be cooperatively illuminatedto indicate that the system is in the IPD state such that the “OK” LEDis flashing, the “leak” LED is flashing, the “dressing full” LED is off,and the “battery critical” LED does not change (on, off, or flashing).Any suitable individual or cooperative LED arrangement is envisioned incertain embodiments. Once a desired negative pressure is reached duringthe IPD state, the one or more indicators can be individually orcooperatively illuminated to indicate that the desired negative pressurehas been reached. For example, in some embodiments, the set of fouricons 114′ can be cooperatively illuminated to indicate that thenegative pressure has been reached such that the “OK” LED is flashing,the “leak” LED is off, the “dressing full” LED is off, and the “batterycritical” LED does not change (on, off, or flashing). In someembodiments, this same illumination pattern can also be used to indicatethat the pump system is functioning properly, such as during the IPDstate to indicate that the pump system is functioning properly duringthe IPD state, in addition to flashing to indicate that the negativepressure has been reached during the IPD state. In various embodiments,in addition to or instead of providing the visual indication using theone or more indicators, other indications can be provided, includingaudible, tactile, and the like.

In some embodiments, the user can pause therapy by activating the switch(e.g., pressing the button), thereby causing the pump system to make atransition from the IPD state 1314 to the standby state 1312. In someembodiments, the pump system can be configured so that the user can onlypause therapy, whereas disconnecting the power source (e.g., removingbatteries) stops therapy. As such, in some embodiments, the pump systemcan potentially time out while in the standby state 1312 and resumeoperation thereby reducing any energy expended while in the standbystate 1312. After being paused by the user, the pump system cantransition from the standby state 1312 to the IPD state 1314 uponreceiving a user input such as a button press. In some embodiments,after being paused by the user, the pump system can automatically makethe transition from the standby state 1312 to the IPD state 1314 whenthe time duration exceeds a threshold. The threshold can be the same ordifferent than the threshold of the standby state 1312 described abovewhen the pump system enters the standby state 1312 after startup 1304.

When the pump system transitions into and remains in the standby state1312, the user can be provided an indication. For example, in someembodiments, all indicators can be deactivated. In some embodiments, thepump system can deactivate an indicator (e.g., an OK indicator) andcause another indicator (e.g., a dressing indicator) to flash or blink.In some embodiments, one or more indicators can blink or flashintermittently or continuously to indicate to the user that the systemis in the standby state. For example, as discussed above with referenceto FIG. 56, in some embodiments, the one or more indicators can includea set of four icons 114′ that include an “OK” indicator which canindicate normal operation of the pump system 100, a “leak” indicatorwhich can indicate the existence of a leak in the pump system 100 orcomponents attached thereto, a “dressing full” indicator which canindicate that a wound dressing is at or near capacity, and a “batterycritical” indicator which can indicate that the battery is at or near acritical level. In some embodiments, the one or more indicators can beindividually or cooperatively illuminated to indicate to the user thatthe system is in the standby state. For example, in some embodiments,the set of four icons 114′ can be cooperatively illuminated to indicatethat the system is in the standby state such that the “OK” LED is off,the “leak” LED is off, the “dressing full” LED is off, and the “batterycritical” LED is off. In some embodiments, this same illuminationpattern can also be used to indicate that the pump system has completedits course of negative pressure wound therapy or to indicate that thebatteries have been depleted, in addition to indicating that the pump isin the standby state. Any suitable cooperative LED arrangement isenvisioned in certain embodiments. In various embodiments, in additionto or instead of providing the visual indication using the one or moreindicators, other indications can be provided, including audible,tactile, and the like. In some embodiments, therapy can be suspendedwhile the pump system remains in the standby state 1312. For example,the source of negative pressure can be deactivated (or turned off),which provides the indication to the user that the pump system is in thestandby state 1312.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, the pump system can transition from theinitial pump down state 1314 into a leak state 1316 when a number ofretry cycles exceeds a retry limit and/or when a duty cycle of the pump(explained below) is determined to exceed a duty cycle limit. In someembodiments, exceeding a retry limit and/or duty cycle limit can reflectthe presence of a leak in the system. In some embodiments, the pumpsystem can transition from the IPD state 1314 to the leak state 1316when a threshold pressure is not reached within a desired amount oftime. The inability for the threshold pressure to reach the thresholdpressure within a desired amount of time can reflect the presence of aleak in the system. In some embodiments, an indicator (e.g., a leakindicator or dressing indicator) can blink or flash intermittently orcontinuously to indicate to the user the presence of a leak in thesystem. In some embodiments, one or more indicators can blink or flashintermittently or continuously to indicate to the user the presence of aleak. For example, as discussed above with reference to FIG. 56, in someembodiments, the one or more indicators can include a set of four icons114′ that include an “OK” indicator which can indicate normal operationof the pump system 100, a “leak” indicator which can indicate theexistence of a leak in the pump system 100 or components attachedthereto, a “dressing full” indicator which can indicate that a wounddressing is at or near capacity, and a “battery critical” indicatorwhich can indicate that the battery is at or near a critical level. Insome embodiments, the one or more indicators can be individually orcooperatively illuminated to indicate to the user the presence of aleak. For example, in some embodiments, the set of four icons 114′ canbe cooperatively illuminated to indicate the presence of a leak suchthat the “OK” LED is off, the “leak” LED is flashing, the “dressingfull” LED is off, and the “battery critical” LED does not change (on,off, or flashing). Any suitable cooperative LED arrangement isenvisioned in certain embodiments. In various embodiments, in additionto or instead of providing the visual indication using the one or moreindicators, other indications can be provided, including audible,tactile, and the like.

After entering the leak state 1316, the pump system can transition fromthe leak state 1316 to the IPD state 1314 upon receiving a user inputsuch as a button press. This can advantageously give the user some timeto mitigate or remove the leak, such as by checking the connections ofthe wound dressing and/or checking the seal of the wound dressing aroundthe wound. In some embodiments, the pump system can monitor the durationof time the pump system remains in the leak state 1316. This can beaccomplished, for example, by maintaining a timer (in firmware,software, hardware or any combination thereof), which can be reset andstarted when the pump system transitions into the leak state 1316. Insome embodiments, after entering the leak state 1316, the pump systemcan automatically make the transition from the leak state 1316 to theIPD state 1314 when the time duration exceeds a threshold. The thresholdcan be the same or different than the other time thresholds describedherein, such as that of the standby state 1312 to the IPD state 1314.The threshold can be the same or different depending on the state ormode prior to transitioning to the leak state 1316 (e.g., the IPD state1314 or the maintenance mode 1350). In some embodiments, such thresholdcan be a preset value, such as between 1 minute or less and 1 hour ormore. In some embodiments, the threshold can be set or changed by theuser. In some embodiments, the threshold can be varied based on variousoperating conditions or on any combination thereof. For example, as thepump system nears the end of life (as is explained below), the thresholdcan be decreased provided the battery has sufficient capacity remaining.This can advantageously ensure that the battery is more efficiently usedover the lifespan of the pump system by reducing the amount of timespent in the leak state 1316 and utilizing more of the battery byactivating the pump sooner. The pump system can transition into othermodes or states, such as the maintenance mode 1350, after activating theswitch or automatically after exceeding the threshold. In someembodiments, the pump system can transition to the IPD state 1314 or themaintenance mode 1350 depending on operating conditions, such as thepressure at the time of the transition.

As noted above, in some embodiments, the pump system can be configuredto operate in a canisterless system, in which the wound dressing retainsexudate aspirated from the wound. Such dressing can include a filter,such as a hydrophobic filter, that prevents passage of liquidsdownstream of the dressing (toward the pump system). In otherembodiments, the pump system can be configured to operate in systemhaving a canister for storing at least part of exudate aspirated fromthe wound. Such canister can include a filter, such as a hydrophobicfilter, that prevents passage of liquids downstream of the dressing(toward the pump system). In yet other embodiments, both the dressingand the canister can include filters that prevent passage of liquidsdownstream of the dressing and the canister.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, the pump system can be configured totransition from the initial pump down state 1314 into a filter blockedstate 1318 when the system determines that the filter, such as a wounddressing filter, has encountered a blockage (e.g., caused by the wounddressing being filled with exudate to capacity or nearly to capacity).Example algorithms for determining that the filter has encountered ablockage will be discussed in further detail below. In some embodiments,an indicator (e.g., a filter blocked indicator) can blink or flashintermittently or continuously to indicate to the user the presence of ablockage. In some embodiments, one or more indicators can blink or flashintermittently or continuously to indicate to the user the presence of ablockage. For example, as discussed above with reference to FIG. 56, insome embodiments, the one or more indicators can include a set of fouricons 114′ that include an “OK” indicator which can indicate normaloperation of the pump system 100, a “leak” indicator which can indicatethe existence of a leak in the pump system 100 or components attachedthereto, a “dressing full” indicator which can indicate that a wounddressing is at or near capacity, and a “battery critical” indicatorwhich can indicate that the battery is at or near a critical level. Insome embodiments, the one or more indicators can be individually orcooperatively illuminated to indicate to the user the presence of ablockage. For example, in some embodiments, the set of four icons 114′can be cooperatively illuminated to indicate the presence of a blockagesuch that the “OK” LED is off, the “leak” LED is off, the “dressingfull” LED is flashing, and the “battery critical” LED does not change(on, off, or flashing). Any suitable cooperative LED arrangement isenvisioned in certain embodiments. In various embodiments, in additionto or instead of providing the visual indication using the one or moreindicators, other indications can be provided, including audible,tactile, and the like. In some embodiments, the transition to the filterblocked state 1318 can be made when a canister filter is blocked (e.g.,caused by the canister being full or nearly full).

After entering the filter blocked state 1316, the pump system cantransition from the filter blocked state 1318 to the IPD state 1314 uponreceiving a user input such as a button press. This can advantageouslygive the user an opportunity to mitigate or remove the blockage, such asby changing the wound dressing (and/or the canister). In someembodiments, the pump system can monitor the duration of time the pumpsystem remains in the filter blocked state 1318. This can beaccomplished, for example, by maintaining a timer (in firmware,software, hardware or any combination thereof), which can be reset andstarted when the pump system transitions into the filter blocked state1318. In some embodiments, after entering the filter blocked state 1318,the pump system can automatically make the transition from the filterblocked state 1318 to the IPD state 1314 when the time duration exceedsa threshold. The threshold can be the same or different than the othertime thresholds described herein, such as that of the standby state 1312to the IPD state 1314 and/or the leak state 1316 to the IPD state 1314.The threshold can be the same or different depending on the state ormode prior to transitioning to the filter blocked state 1318 (e.g., theIPD state 1314 or the maintenance mode 1350). In some embodiments, suchthreshold can be a preset value, such as between 1 minute or less and 1hour or more. In some embodiments, the threshold can be set or changedby the user. In some embodiments, the threshold can be varied based onvarious operating conditions or on any combination thereof. For example,as the pump system nears the end of life (as is explained below), thethreshold can be decreased provided the battery has sufficient capacityremaining. This can advantageously ensure that the battery is moreefficiently used over the lifespan of the pump system by reducing theamount of time spent in the filter blocked state 1316 and utilizing moreof the battery by activating the pump sooner. The pump system cantransition into other modes or states, such as the maintenance mode1350, after activating the switch or automatically after exceeding thethreshold. In some embodiments, the pump system can transition to theIPD state 1314 or the maintenance mode 1350 depending on operatingconditions, such as the pressure at the time of the transition.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, during the IPD state 1314, once the pumpsystem has detected that the pressure within the pump system or someportion thereof, such as a fluid flow path between a source of negativepressure and a wound dressing, is at or around the low pressurethreshold, the pump system can transition into a maintenance mode 1350and, in particular, to the monitor state 1352. For example, the lowpressure threshold can be approximately −90 mmHg. In some embodiments,the low pressure threshold can be between approximately −50 mmHg andapproximately −250 mmHg, between approximately −75 mmHg andapproximately −125 mmHg, between approximately −80 mmHg and −115 mmHg,approximately −94 mmHg, any value or subrange within these ranges, orany other value as desired.

During the maintenance mode 1350, the pump system can advantageouslymonitor and maintain the pressure within the pump system or some portionthereof, such as a fluid flow path between a source of negative pressureand a wound dressing, within a target pressure range (or operatingrange). For example, in some embodiments, during the maintenance mode1350, the pump system can maintain the pump system or some portionthereof between a high pressure threshold and a low pressure threshold.For example, the high pressure threshold can be approximately −70 mmHg.In some embodiments, the high pressure threshold can be betweenapproximately −40 mmHg and approximately −200 mmHg, betweenapproximately −60 mmHg and approximately −100 mmHg, betweenapproximately −70 mmHg and −80 mmHg, approximately −71 mmHg,approximately −67 mmHg, any value or subrange within these ranges, orany other value as desired. The low pressure threshold can beapproximately −90 mmHg. In some embodiments, the low pressure thresholdduring the maintenance mode 1350 can be the same as the low pressurethreshold during the IPD state 1314. In some embodiments, the lowpressure threshold during the maintenance mode 1350 can be differentfrom the low pressure threshold during the IPD state 1314. As shown inthe illustrated embodiment, the maintenance mode 1350 can include amonitor state 1352 and a maintenance pump down (“MPD”) state 1354.

In some embodiments, one or more indicators can blink or flashintermittently or continuously to indicate to the user that the systemis in the MPD state. For example, as discussed above with reference toFIG. 56, in some embodiments, the one or more indicators can include aset of four icons 114′ that include an “OK” indicator which can indicatenormal operation of the pump system 100, a “leak” indicator which canindicate the existence of a leak in the pump system 100 or componentsattached thereto, a “dressing full” indicator which can indicate that awound dressing is at or near capacity, and a “battery critical”indicator which can indicate that the battery is at or near a criticallevel. In some embodiments, the one or more indicators can beindividually or cooperatively illuminated to indicate to the user thatthe system is in the MPD state. For example, in some embodiments, theset of four icons 114′ can be cooperatively illuminated to indicate thatthe system is in the MPD state such that the “OK” LED is flashing, the“leak” LED is off, the “dressing full” LED is off, and the “batterycritical” LED does not change (on, off, or flashing). Any suitablecooperative LED arrangement is envisioned in certain embodiments. Once adesired negative pressure is reached during the MPD state, the one ormore indicators can be cooperatively illuminated to indicate that thenegative pressure has been reached. For example, in some embodiments,the set of four icons 114′ can be cooperatively illuminated to indicatethat the negative pressure has been reached such that the “OK” LED isflashing, the “leak” LED is off, the “dressing full” LED is off, and the“battery critical” LED does not change (on, off, or flashing). In someembodiments, this same illumination pattern can also be used to indicatethat the pump system is functioning properly, such as during the MPDstate to indicate that the pump system is functioning properly duringthe MPD state, in addition to flashing to indicate that the negativepressure has been reached during the MPD state. In various embodiments,in addition to or instead of providing the visual indication using theone or more indicators, other indications can be provided, includingaudible, tactile, and the like.

During the monitor state 1352, the pump system can monitor the pressurein the pump system or some portion thereof, such as a fluid flow pathbetween a source of negative pressure and a wound dressing, to ensurethat the pressure within the pump system or the monitored portionthereof is maintained between a high pressure threshold and a lowpressure threshold. The source of negative pressure can be deactivatedduring the monitor state 1352. The pump system can intermittently and/orcontinuously monitor the pressure in the pump system or some portionthereof. For example, the pump system can monitor the pressure in thepump system or some portion thereof at a preset sampling rate ofapproximately 1 second. In some embodiments, the sampling rate can bebetween approximately 50 ms and approximately 5 seconds, betweenapproximately 200 ms and 2 seconds, between approximately 500 ms and 2seconds, approximately 1 second, any value and/or subrange with theseranges, or any other sampling rate as desired. In some embodiments, thesampling rate during the monitor state 1352 can be less than thesampling rate during the IPD state 1314 to advantageously reduce powerusage and extend the life of the power source. A lower sampling rate canbe used in some embodiments as the rate of pressure change during themonitor state 1352 (e.g., when the source of negative pressure isdeactivated) can be less than the rate of pressure change when thesource of negative pressure is activated. In some embodiments, the pumpsystem can also calculate the rate of pressure change to estimate theamount of time until the pump system reaches a desired pressure, such asa low pressure threshold.

In some embodiments, one or more indicators can blink or flashintermittently or continuously to indicate to the user that the systemis in the monitor state. For example, as discussed above with referenceto FIG. 56, in some embodiments, the one or more indicators can includea set of four icons 114′ that include an “OK” indicator which canindicate normal operation of the pump system 100, a “leak” indicatorwhich can indicate the existence of a leak in the pump system 100 orcomponents attached thereto, a “dressing full” indicator which canindicate that a wound dressing is at or near capacity, and a “batterycritical” indicator which can indicate that the battery is at or near acritical level. In some embodiments, the one or more indicators can beindividually or cooperatively illuminated to indicate to the user thatthe system is in the monitor state. For example, in some embodiments,the set of four icons 114′ can be cooperatively illuminated to indicatethat the system is in the monitor state such that the “OK” LED isflashing, the “leak” LED is off, the “dressing full” LED is off, and the“battery critical” LED does not change (on, off, or flashing). In someembodiments, this same illumination pattern can also be used to indicatethat the pump system is functioning properly during the monitor state,in addition to flashing to indicate that the system is in the monitorstate. Any suitable cooperative LED arrangement is envisioned in certainembodiments. In various embodiments, in addition to or instead ofproviding the visual indication using the one or more indicators, otherindications can be provided, including audible, tactile, and the like.

The pump system can stay in the monitor state 1352 until the pump systemdetects that the pressure in the pump system or some portion thereof,such as a fluid flow path between a source of negative pressure and awound dressing, is at or around a high pressure threshold. Upondetecting that the pump system or some portion thereof is at or aroundthe high pressure threshold, the pump system can transition to the MPDstate 1354. During the MPD state 1354, the pump system can activate thesource of negative pressure to begin therapy and reduce pressure in thesystem or some portion thereof until the pressure is at or near the lowpressure threshold. In some embodiments, the low pressure threshold canbe the same or similar to the low pressure threshold discussed inconnection with the IPD state 1314. In some embodiments, the lowpressure threshold can be different from that in the IPD state 1314.

The pump system can continually monitor the pressure in the pump systemat a preset sampling rate. In some embodiments, the sampling rate can bethe same or similar to the low pressure threshold discussed inconnection with the IPD state 1314. In some embodiments, the samplingrate can be different from the sampling rate during the IPD state 1314.In some embodiments, the pump system can also calculate the rate ofpressure change to estimate the amount of time until the pump systemreaches a desired pressure, such as the low pressure threshold. When thepump system detects that the pressure in the pump system or some portionthereof is at or around the low pressure threshold, the pump system cantransition back to the monitor state 1352.

With reference back to the embodiment discussed in connection with FIG.63, in some embodiments, the user can pause therapy by activating theswitch (e.g., pressing the button), thereby causing the pump system tomake a transition from the maintenance mode 1350 to the standby state1312. After being paused by the user, the pump system can transitionfrom the standby state 1312 to the IPD state 1314 upon receiving a userinput such as a button press. In some embodiments, after being paused bythe user, the pump system can automatically make the transition from thestandby state 1312 to the IPD state 1314 when the time duration exceedsa threshold. The threshold can be the same or different than thethresholds discussed above, such as the threshold when the pump systementers the standby state 1312 from the IPD state 1314 from a buttonpress. In some embodiments, such threshold can be a preset value, suchas between 1 minute or less and 1 hour or more. In some embodiments, thethreshold can be set or changed by the user. In some embodiments, thethreshold can be varied based on various operating conditions or on anycombination thereof. For example, as the pump system nears the end oflife (as is explained below), the threshold can be decreased providedthe battery has sufficient capacity remaining. In some embodiments, thepump system can transition into the maintenance mode 1350 afteractivating the switch or automatically after exceeding the threshold. Insome embodiments, the pump system can transition to the IPD state 1314or the maintenance mode 1350 depending on operating conditions, such asthe pressure at the time of the transition.

When the pump system transitions into and remains in the standby state1312, the user can be provided an indication. For example, in someembodiments, all indicators can be deactivated. In some embodiments, thepump system can deactivate an indicator (e.g., an OK indicator) andcause another indicator (e.g., a dressing indicator) to flash or blink.In some embodiments, therapy can be suspended while the pump systemremains in the standby state 1312. For example, the source of negativepressure can be deactivated (or turned off), which provides theindication to the user that the pump system is in the standby state1312.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, the pump system can transition from themaintenance mode 1350 into a leak state 1316 when a threshold pressureis not reached within a desired amount of time. The inability for thethreshold pressure to reach the threshold pressure within a desiredamount of time can reflect the presence of a leak in the system. In someembodiments, the pump system can transition from the maintenance mode1350 to the leak state 1316 when a number of retry cycles exceeds aretry limit and/or when the duty cycle of the pump is determined toexceed a duty cycle limit. In some embodiments, exceeding a retry limitand/or duty cycle limit can reflect the presence of a leak in thesystem. In some embodiments, an indicator (e.g., a leak indicator ordressing indicator) can blink or flash intermittently or continuously toindicate to the user the presence of a leak in the system.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, the pump system can be configured totransition from the maintenance mode 1350 into a filter blocked state1318 when the system determines that the filter, such as the wounddressing filter (and/or the canister filter), has encountered a blockage(e.g., caused by the wound dressing being filled with exudate tocapacity or nearly to capacity). Example algorithms for determining thatthe filter has encountered a blockage will be discussed in furtherdetail below. In some embodiments, an indicator (e.g., a filter blockedindicator) can blink or flash intermittently or continuously to indicateto the user the presence of a blockage.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, the pump system can be configured tomonitor the remaining capacity or life of the power source (e.g., byperiodically reading or sampling the battery voltage, current, etc.).The pump system can be configured to indicate to the user the remainingcapacity. For example, if the power source is determined to have anormal remaining capacity (e.g., as a result of comparison to athreshold, such as 2.7V, 2.6V, 2.5V, etc.), an indicator (e.g., abattery indicator) can be deactivated. If the power source is determinedto have low remaining capacity, the pump system, can provide anindication to the user by, for example, causing an indicator (e.g., abattery indicator) to blink or flash. In some embodiments, an indicator(e.g., a battery indicator) can be configured to be blinking or flashingintermittently or continuously regardless of the state the pump systemis in or only in particular states.

In some embodiments, when the remaining capacity of the power source isdetermined to be at or near a critical level (e.g., as a result ofcomparison to a threshold, such as 2.4V, 2.3V, 2.2V, etc.), the pumpsystem can transition into an under voltage or battery critical state1392. In some embodiments, the pump system can remain in this stateuntil the capacity of the power source is increased, such as byreplacing or recharging the power source. The pump system can deactivatetherapy while remaining in the battery critical state 1392. In addition,the pump system can be configured to indicate to the user that the powersource is at or near the critical level by, for example, deactivatingall indicators. In some embodiments, when the pause/resume button ispressed after the pump system has transitioned to the under voltagestate 1392, the pump system can be configured to indicate that thedevice has not yet reached its end of life (EOL) by, for example,flashing a battery indicator LED.

With continued reference to the embodiment discussed in connection withFIG. 63, in some embodiments, the pump system can be configured toprovide therapy for a predetermined period of time, such asapproximately 1 day, 2-10 days, up to 30 days, etc. following a firstactivation. In some embodiments, such period of time can be a presetvalue, changed by the user, and/or varied based on various operatingconditions or on any combination thereof. The pump system can bedisposed upon the expiration of such period of time. Once the pumpsystem has been activated, the pump system can monitor the duration ithas remained active. In some embodiments, the pump system can monitorthe cumulative duration the system has remained active. This can beaccomplished, for example, by maintaining a timer (in firmware,software, hardware or any combination thereof), that reflects suchduration.

When the duration reaches or exceeds a threshold (e.g., 10 days), thepump system can transition to an end of life (EOL) state 1390. The pumpsystem can deactivate therapy while remaining in state 1390 and toindicate to the user that the end of the pump system's usable life hasbeen reached. For example, the pump system can deactivate all indicatorsand/or deactivate the button. In some embodiments, when the pump systemis disposable, transitioning to the end of life state 1390 means thatthe pump system can be disposed of. The pump system can disablereactivation of the pump system once the end of life has been reached.For example, the pump system can be configured to not allow reactivationeven if the power source is disconnected and reconnected later, whichcan be accomplished by storing an indication, value, flag, etc. in theread only memory.

FIG. 64 illustrates an exemplary graph 1400 of pressure versus time whenthe negative pressure source is active, such as during the maintenancemode 1350, according to some embodiments. As illustrated by line 1410,the system can enter the monitor state 1352 upon detecting that thepressure in the pump system or some portion thereof, such as a fluidflow path between a source of negative pressure and a wound dressing, isat or near a low pressure threshold 1402. In the illustrated embodiment,the low pressure threshold can be approximately −100 mmHg although otherlow pressure thresholds can be chosen as discussed above. During themonitor state 1352, the pressure in the pump system or some portionthereof may begin to gradually decay due to the source of negativepressure being deactivated and the existence of minor leakages in thesystem. As is illustrated, the pump system can monitor pressure over theperiod of time a, as represented by interval 1430. In some embodiments,the pressure can be sampled over the interval 1430 after a transienttime period has elapsed. For example, in some embodiments, the transienttime period can be measured from when the monitor state 1352 begins.After the transient time period has elapsed, pressure can be sampled inconsecutive samples, and two or more of the consecutive samples can beaveraged.

When the system detects that the pressure in the pump system or someportion thereof is at or near the high pressure threshold 1412, thesystem can switch to the MPD state 1354 and reactivate the source ofnegative pressure to lower the pressure in the pump system or someportion thereof as illustrated by line 1420. In the illustratedembodiment, the high pressure threshold can be approximately −60 mmHgalthough other high pressure thresholds can be chosen as discussedabove. As is illustrated, the pump system can activate the over theperiod of time b, as represented by interval 1432. When the systemdetects that the pressure in the pump system or some portion thereof isat or near the low pressure threshold 1422, the system can switch backto the monitor state 1352 and deactivate the source of negativepressure. This process can be repeated as desired.

In some embodiments, the pump assembly can be configured to monitor theduty cycle of the source of negative pressure (e.g., a pump). As is usedherein, “duty cycle” reflects the amount of time the source of negativepressure is active or running over a period of time. In other words, theduty cycle can reflect time that the source of negative pressure is inan active state as a fraction of total time under consideration. Forexample, as described above, in some embodiments, the pump system cantransition from the IPD state 1314 or the maintenance mode 1350 to theleak state 1316 when, for example, the duty cycle of the pump isdetermined to exceed a duty cycle limit. In such a case, exceeding theduty cycle limit can reflect the presence of a leak in the system. Insome embodiments, the duty cycle (DC) of the pump over the periodillustrated between intervals 1410 and 1420 (i.e., a +b) can beexpressed, on percent scale, as:

DC=100%*[b/(a+b)].

In some embodiments, the pump assembly can include a controller, such ascontroller 1114 or 1202, configured to monitor the duty cycle of thesource of negative pressure. Duty cycle measurements can indicate rateof flow through the system and reflect a level of activity of the sourceof negative pressure. For example, duty cycle can indicate that thesource of negative pressure is operating normally, working hard, workingextremely hard, etc. Moreover, duty cycle measurements, such as periodicduty cycle measurements, can reflect various operating conditions, suchas presence, rate, and/or severity of one or more leaks in the system,rate of flow of fluid (e.g., air, liquid and/or solid exudate, etc.)aspirated from a wound, and the like. Based on the duty cyclemeasurements, such as by comparing the measured duty cycle to a dutycycle threshold (determined in calibration or at runtime), thecontroller can execute and/or be programmed to execute algorithms orlogic that control the operation of the system in accordance withvarious system requirements. For example, duty cycle measurements canindicate presence of a high leak in the system, and the controller canbe programmed to indicate this condition to a user (e.g., patient,caregiver, physician, etc.) and/or temporarily suspend or pauseoperation of the source of negative pressure in order to conserve power.

In some embodiments, the pump system 1000, 1100, or 1200 can beconfigured to periodically monitor the duty cycle, such as once betweenevery 10 seconds or less and 5 minutes or more. In some embodiments, thepump assembly can be configured to monitor the duty cycle once perminute.

For example, in order to determine the duty cycle, the pump system 1000,1100, 1200 can be configured to monitor the duration of time that thepump has been active (e.g., the pump run time) and/or inactive. In someembodiments, the pump system (e.g., controller 1114, 1202) can beconfigured to compare the determined duty cycle to a duty cyclethreshold, which can be selected from the range between 1% or less and50% or more. The comparison can, for example, indicate presence of aleak in the system. In other words, if the pump remains active over aperiod of time so that the duty cycle threshold is reached or exceeded,the source of negative pressure may be working too hard to overcome theleak. In such cases, as explained above, the pump assembly can beconfigured to suspend or pause the delivery of therapy. The pumpassembly can be configured to provide an indication to the user that thepump is working hard (e.g., duty cycle exceeds the duty cycle threshold)by, for example, deactivating the source of negative pressure,activating one or more indicators, and the like. In some embodiments,the duty cycle threshold can be a preset value, set or changed by theuser, and/or varied based on various operating conditions or on anycombination thereof. In some embodiments, while the duty cycle indicatesthe level of pump activity, other metrics, such as pump speed, can beused for measuring the level of pump activity. In certain embodiments,the rate of flow of fluid can be measured directly, such as by using aflow meter.

In some embodiments, the pump system 1000, 1100, or 1200 determines andadjusts the duty cycle threshold at run time (or dynamically). Forexample, the controller 1114 or 1202 can be configured to determine theduty cycle threshold periodically and/or continuously, such asapproximately every 1 second or less, 30 seconds or less or more, 1minute or less or more, 10 minutes or less or more, 30 minutes or lessor more, 1 hour or less or more, and so on. The duty cycle threshold canbe based at least in part on a capacity of the power source 1108 or 1216and an operational time of the apparatus (e.g., pump system 100 shown inFIG. 57A, and pump systems 1000, 1100, or 1200 shown in FIGS. 60, 61,and 62). As explained above, the pump system can be configured toprovide therapy for a predetermined period of time, and deactivateitself a predetermined period of time after an initial activation. Forinstance, such predetermined period of time (or lifetime threshold) canbe between 1 day or less or 10 days or more, such as 7 days (or 168hours), 10 days (or 240 hours), etc. The power source 1108 or 1216 canbe configured or selected to have sufficient capacity to providesufficient power to the pump system 100, 1000, 1100, or 1200 to operatefor at least an amount of time that equals the lifetime threshold. Insome embodiments, the apparatus (e.g., via controller 1114 or 1202) canbe configured to determine the operational time based on a total elapsedtime since an initial activation of the apparatus and disable activationof the source of negative pressure when the operational time reaches thelifetime threshold.

According to some aspects, adjusting the duty cycle threshold may bebeneficial for several reasons. In some embodiments, the duty cyclethreshold can represent a balance between the desire to provide therapyto the user with none or fewer interruptions and the need to conservepower. For example, in a situation when there is a leak in the systemand leak detection is performed based at least partly on monitoring theduty cycle of the pump and comparing the monitored duty cycle to theduty cycle threshold, the pump system 100, 1000, 1100, or 1200 can beconfigured to provide therapy for a certain period of time beforeproviding an indication to the user that a leak has been detected, whichcan include deactivating the delivery of therapy. After the leak hasbeen remedied, delivery of therapy can be restarted. However, increasingthe duty cycle threshold can advantageously result in fewerinterruptions of the delivery of therapy.

In some embodiments, the duty cycle can be calculated (e.g., bycontroller 1114 or 1202) periodically and/or dynamically duringoperation of the pump system. As discussed above, in some embodiments,the duty cycle threshold can be calculated based on an estimation and/orcalculation of the remaining or residual battery life of the pumpsystem. Duty cycle estimations and/or calculations that are a functionof residual battery life are dynamic because battery life decreasesduring operation of the pump system (absent any battery charge). As aresult, estimated and/or calculated duty cycle thresholds will beadjusted as the residual battery life decreases and end of life is beingapproached. For example, in some embodiments, the energy (for example,expressed in joules) consumed by the pump system can be tracked over atime period to determine the amount of residual battery life at anygiven time. In some embodiments, the actual energy consumed by the pumpsystem can be tracked, or the estimated number of joules consumed by thepump system can be tracked.

In some embodiments, the duty cycle threshold can be adjusted based onthe determination of the residual battery life. For example, supposethat the pump system is configured to operate for 10 days. During thefirst day, the duty cycle threshold can be conservatively set to a lowervalue, such as for example 10%, in order to conserve battery life sothat the pump system is able to operate for another 9 days. Now supposethat on day 5 of operation, the residual battery life indicates 75% ofremaining battery capacity (not 50% remaining capacity as would beexpected half-way through the operational period), and suppose thatbased on the operational history over the first 5 days of operation, itis estimated that the pump system will consume at most 50% of batterycapacity over the last 5 days of operation. The estimated energyconsumption of the pump system can be determined in various ways,including taking a conservative estimate of the pump system operating inthe presence of one or more leaks, which may be severe. In this example,because the estimated remaining battery capacity on day 5 (or 75%)exceeds the estimated capacity needed for pump operation through the endof life (or 50%), the duty cycle threshold can be increased by 25% (to12.5%) or by another suitable increment. In another example, the dutycycle threshold can be decreased because the remaining battery capacityis below expected capacity due to, for instance, leaks that had beenencountered during operation. In certain embodiments, the duty cyclethreshold can be set between minimum and maximum values.

In some embodiments, duty cycle threshold (DC) can be determined asfollows. This determination can be performed by a controller (e.g., bycontroller 1114 or 1202). In the following calculations,T_(predicted,run) is the estimated time during which the pump isexpected to be active or running (such as in IPD state, MPD state,etc.), T_(predicted,wait) is the estimated time during which the pump isexpected to be inactive or idle (such as in monitor state, pause state,etc.), and T_(residual) is remaining amount of time until end of life isreached. T_(predicted,run) can determined as the amount of residual time(T_(residual)) the pump system is expected to be active, which can beexpressed in terms of the duty cycle threshold as follows:

T _(predicted,run) =T _(residual)*DC  (1)

T_(predicted,wait) can be determined as the amount of residual time(T_(residual)) the pump system is expected to be idle, which can beexpressed in terms of DC as follows:

T _(predicted,wait) =T _(residual)*(1−DC)  (2)

P_(run) and P_(wait) are estimated power consumptions when the pump isrunning and idle respectively. These values can be determined using oneor more of the following techniques: taking into account historicaloperation of the device, performing a conservative estimate (which, asexplained above, can include expecting the system to operate in presenceof one or more severe leaks), performing a less conservative estimate(which can include expecting the system to operate in the presence ofone or more manageable leaks), and the like. E_(residual) is theestimated residual capacity of the power source, which can be estimatedand/or measured. As is shown in the following equation, E_(residual) canalso be expressed as the sum of the estimated energy that will beconsumed during periods of activity (T_(predicted,run) multiplied byP_(run)) and the estimated energy that will be consumed during periodsof inactivity (T_(predicted,wait) multiplied by P_(wait)).

E _(residual)=(T _(residual)*DC*P _(run))+(T _(residual)*(1−DC)*P_(wait))  (3)

Simplifying equation (3) yields:

E _(residual) =T _(residual)*(DC*P _(run)+(1−DC)*P _(wait))  (4)

Dividing equation (4) by

$\begin{matrix}{\frac{E_{residual}}{T_{residual}} = {{{DC}*P_{run}} + P_{wait} - {{DC}*P_{wait}}}} & (5)\end{matrix}$

Rearranging equation (3) yields:

$\begin{matrix}{{\frac{E_{residual}}{T_{residual}} - P_{wait}} = {{DC}*( {P_{run} - P_{wait}} )}} & (6)\end{matrix}$

Solving for the duty cycle (DC) yields:

$\begin{matrix}{{DC} = \frac{\frac{E_{residual}}{T_{residual}} - P_{wait}}{P_{run} - P_{wait}}} & (7)\end{matrix}$

Accordingly, equation (7) can be used to determine the dynamic dutycycle threshold. This determination can be performed periodically.

Additional details of pump system control are disclosed in U.S. Pat. No.8,734,425, titled “PRESSURE CONTROL APPARATUS,” U.S. Pat. No. 8,905,985,titled “SYSTEMS AND METHODS FOR CONTROLLING OPERATION OF A REDUCEDPRESSURE THERAPY SYSTEM,” and U.S. Patent Publication No. 2015/0051560,titled “CONTROLLING OPERATION OF A REDUCED PRESSURE THERAPY SYSTEM BASEDON DYNAMIC DUTY CYCLE THRESHOLD DETERMINATION,” which are incorporatedby reference in their entireties as if made part of this disclosure.

In some embodiments, the pressure during the IPD or MPD state can besampled after a preset period of time as elapsed from when the IPD orMPD state was initiated. After this time period elapses, the pressurecan be sampled in consecutive samples, and two or more of theconsecutive samples can be averaged. In some embodiments, sampling ofthe pressure can be synchronized with the drive signal. For example,sampling of the pressure within the pump system or some portion thereof,such as a fluid flow path between a source of negative pressure and awound dressing, can be performed when the drive signal is approximatelyat an amplitude that is substantially at an offset (explained below)and/or at a zero value. In some embodiments, two or more groups ofconsecutive pressure samples can be averaged to minimize measurementerrors due to pressure fluctuations caused by operation of the motor. Insome embodiments, averaging two or more groups of consecutive pressuresamples can compensate for the time needed to detect the zero value whenthe pressure samples are synchronized at a zero value. Movement of thepump assembly can highly influence pressure within the pump system, suchas a manifold of the pump system. By synchronizing sampling of thepressure with the offset and/or zero value of the drive signal, anymeasurement errors due to pressure fluctuations caused by operation ofthe motor can be reduced. In some embodiments, sampling of the pressurecan be synchronized with the local maxima and/or local minima of thedrive signal. In some embodiments, sampling of the pressure can besynchronized with certain portions of the drive signal, such as portionsof the drive signal with a negative rate of change and/or a positiverate of change.

In some embodiments, the pressure can be sampled one or more times at oraround the one or more selected sampling amplitudes such as the offsetand/or zero value, local maxima, and/or local minima. This canbeneficially reduce the likelihood of sampling errors and compensate forthe delay elapsed between detection of the one or more selected samplingamplitudes and sampling of the pressure. For example, in someembodiments, the pump system can take 8 consecutive samples atapproximately each offset and/or zero value. Accordingly, the pumpsystem can take 16 samples over a single period of the drive signal. Insome embodiments, the pump system can average some or all of the samplestaken over a period.

Pump Actuation and Control

In any embodiments disclosed herein, the performance and efficiency ofthe pump can be improved by selecting a suitable signal or waveform fordriving the actuator (e.g., coil 600 of the pump system 100). A suitabledriving waveform can be applied to the coil by the controller (e.g.,controllers 1006, 1114 and/or driver module 1220). In any embodimentsdisclosed herein, the pressure differential across a diaphragm and theoutlet valve of a pump (e.g., diaphragm 550 of pump system 100) when thediaphragm is drawing against vacuum (or removing gas from the fluid flowpathway) can be determined as the sum of the pressure drop across thevalves and the vacuum level under the dressing. For example, in anyembodiments disclosed herein, the negative pressure range can beapproximately −80 mmHg, which means that the vacuum level of up to 80mmHg can affect the pressure drop across the diaphragm. When thediaphragm is expelling removed fluid (e.g., expelling removed gas to theatmosphere), the pressure differential across the diaphragm and theoutlet valve can be determined as the pressure drop across the valves.In other words, when gas is being expelled, the pressure differentialacross the diaphragm and the outlet valve is substantially equivalent tothe pressure drop across the valves.

In any embodiments disclosed herein, the force for expelling removed gascan be smaller than the force for drawing vacuum (e.g., removing gasfrom the fluid flow pathway). If a symmetric signal, such as a squarewave or sine wave of equal positive and negative amplitude is applied tothe coil, the diaphragm may oscillate about a point that is not itsrelaxed center state, which may reduce the total diaphragm travel,thereby reducing efficiency.

FIG. 65 represents an exemplary drive signal for a source of negativepressure according to some embodiments. In any embodiments disclosedherein, a diaphragm can be driven by an offset sinusoidal (or sine)drive signal 1510. For example, the drive signal can be applied to theactuator of the pump, such as coil 600, thereby causing the diaphragm toflex and deflect. FIG. 65 illustrates an offset sine waveform 1510 thatcan be applied to the actuator according to some embodiments. The x-axisrepresents time and the y-axis represents amplitude, such as voltage.Although the illustrated amplitude of the sine wave 1510 is the voltage,current can be used for driving the diaphragm.

The sine wave 1510 is offset from 0 V as is shown by line 1512, which isabout 0.4 V. Any suitable offset can be used, such as 0.05 V, 0.1 V,0.65 V, etc. The offset can also be negative. As will be described infurther detail below, in some embodiments, the offset can be variabledepending on operating conditions of the pump system, such as thecurrent and/or desired pressure in the pump system or some portionthereof. The sine wave 1510 can be a signal of a suitable magnitude,such as between −2.7 V and 3.3 V as illustrated in sine wave 1510. Inany embodiments disclosed herein, other suitable magnitudes of voltagecan be used, such as between −1.0 V and 1.0V, −2.0 V and 2.0 V, −4.0 Vand 4.0 V, and so on. As will be described in further detail below, insome embodiments, the magnitude can be variable depending on operatingconditions of the pump system, such as the current and/or desiredpressure in the pump system or some portion thereof. In someembodiments, the resonance frequency of the diaphragm and/or otheroscillating components of the pump assembly can be matched duringoperation of the pump system by modifying the offset and/or magnitude ofthe drive signal during operation. For example, in some embodiments, thedrive signal offset and/or magnitude can be continuously modified suchthat the drive signal oscillates the diaphragm and/or other oscillatingcomponents of the pump assembly at the resonant frequencies that areassociated with the negative pressure being delivered. For example, insome embodiments, the drive signal can be continuously modified duringthe IPD state until a target low pressure threshold is satisfied orexceeded. In some embodiments, the drive signal can be similarlycontinuously modified during the MPD state until a target low pressureis again satisfied or exceeded. By modifying the drive signal offsetand/or magnitude during operation, the pump can be advantageously mademore efficient and quiet during operation. The sine wave 1510 can be ofa suitable frequency, such as approximately 200 Hz as illustrated insine wave 1510. In some embodiments, other suitable frequencies can beused, such as from approximately 50 Hz to approximately 200 Hz, or fromapproximately 25 Hz or less to approximately 300 Hz or more. Otherfrequencies can be used, such as frequencies below 50 Hz and above 200Hz.

In any embodiments disclosed herein, driving the diaphragm with a sinewave signal, such as the offset sine wave 1510 can increase theefficiency of the negative pressure source. For example, because thesine wave 1510 has a single frequency, that frequency can stimulate asingle vibrational or resonance mode of the pump (e.g., the firstvibrational mode of the pump is stimulated provided that the other modeshave a higher natural or resonant frequency). Efficiency can beoptimized if the pump moves or resonates at a single frequency. Forinstance, the axial spring stiffness of the diaphragm and the offset ofthe sine wave can be optimized for greater efficiency. In addition,little or no driving energy may be absorbed by components other than thediaphragm, such as rubber components.

In any embodiments disclosed herein, non-offset sine wave drive signalscan be used. In various embodiments, other periodic signals such ascosine waves, tangent waves, square, triangular waves, sawtooth waves,pulse duration modulated waveform, and the like can be used to drive thediaphragm. Signals driving the diaphragm can be symmetrical orasymmetrical and/or offset or not offset. In some embodiments,non-periodic driving signals can be used.

With continued reference to the exemplary drive signal of FIG. 65, insome embodiments, the sine wave 1510 can be generated via a combinationof one or more other waves. As shown in the illustrated embodiment, two180 degree phase shifted sine waves 1520 and 1530 can be combined togenerate the sine wave 1510. The sine waves 1520 and 1530 can havedifferent amplitudes, such as peak-to-peak amplitudes. In anyembodiments disclosed herein, sine wave 1530 can be subtracted from sinewave 1520 and applied to the source of negative pressure, such as anactuator, as illustrated by schematic 1540. In any embodiments disclosedherein, the sine waves 1520 and 1530 can be phase shifted with respectto each other with any suitable phase shift value selected from therange between 0 and 360 degrees. In various embodiments, sine waves 1520and 1530 can be combined in any linear or non-linear manner.

FIG. 66 illustrates generation of the drive signals, such as the sinewaves 1520 and 1530 illustrated in FIG. 65, according to someembodiments. One or more PWM drive signals 1560 can be generated by acontroller 1550 (e.g., controllers 1006, 1114 and/or driver module1220). These PWM drive signals, which can be represented as acombination of square waves at different frequencies, are filtered by afilter 1570, which can be a low-pass filter. The filter 1570 can beconfigured to filter out all but one frequency component of the PWMdrive signals. In any embodiments disclosed herein, filtering the one ormore PWM drive signals 1560 can produce the sine waves 1520 and 1530. Asshown in the illustrated embodiment, two PWM drive signals 1560(illustrated as top and bottom signals) can be used to produce the sinewaves 1520 and 1530 respectively. Each of the PWM drive signals 1560 canbe a signal having appropriate characteristics, such as amplitude, forgenerating the respective sine wave signal 1520 or 1530.

In any embodiments disclosed herein, the voice coil actuator or motorcan be used as the filter 1570. The voice coil motor can behave as aresonant circuit, such as an LC or RLC circuit, that has low-pass filtercharacteristics. In one embodiment, the motor can have the followingcharacteristics: resistance R=20Ω, inductance L=1 mH, and time constantΣ=50 μs. In any embodiments disclosed herein, a suitable separate filter1570 can be used. In certain embodiments, the filter 1570 can have highpass, band pass, band stop, and/or notch characteristics. In anyembodiments disclosed herein, the sine wave 1510 can be generateddirectly from the one or more PWM signals.

Calibration of Pump Actuation Parameters

In any embodiments disclosed herein, one or more parameters of the drivesignal, such as sine wave 1510, can be varied based on the currentand/or desired operating conditions of the pump system. For example, insome embodiments, parameters such as the offset and/or amplitude of thedrive signal can be varied. Such parameters can be varied based on thecurrent and/or desired pressure for the pump system or some portionthereof, such as a fluid flow path between a source of negative pressureand a wound dressing. As explained below, varying the parameters of thedrive signal can increase efficiency of the pump system, reduce powerconsumption, and reduce noise generated by the components of thenegative pressure source.

In some embodiments, the parameters can be varied to reduce thelikelihood of or eliminate contact between components of the pumpassembly, such as contact between components of a voice coil actuator,such as a support, shaft, or piston, with mechanical stops such as amechanical stop at top dead center (“TDC”), where the diaphragm chambercan be at or near a minimum volume, and bottom dead center (“BDC”),where the diaphragm chamber can be at or near a maximum volume. As thevacuum increases, the offset can be biased more towards BDC and theamplitude may be increased since the piston will exhibit a lesser degreeof movement for a given amplitude at higher vacuum conditions. In someembodiments, the diaphragm can be initially biased towards BDC viacomponents of the pump assembly, such as spring, such that the offsetfor the drive signal can be towards TDC at ambient or atmosphericpressures and reduce in magnitude as the pressures higher negativepressures. By reducing contact between components of the pump assembly,noise, vibration, and harshness of the pump assembly can also bereduced. Moreover, by varying the parameters of the drive signal, theflow through the pump assembly can be maintained at a desired level.

In some embodiments, the parameters can be varied to alter the rate ofpressure decay when the pump assembly is activated. For example, theparameters can be varied such that the rate of pressure decay isgenerally linear.

In any embodiments disclosed herein, the pump system can determine(using the controller) and store (in memory) one or more parameters forthe drive signal. For example, the pump system can determine and storean offset and/or amplitude for one or more target pressures. In someembodiments, the pump system can store an offset and amplitude at threetarget pressures. For example, the pump system can determine and storean amplitude and offset at or around 0 mmHg, at or around −71 mmHg (−9.5kPa), and at or around −94 mmHg (−12.5 kPa). In some embodiments, thesepressures are selected because 0 mmHg corresponds to the initialpressure in the system, −71 mmHg is around the high pressure thresholdin the monitor mode 1350 (as explained above), and −94 mmHg is aroundthe low pressure threshold in the monitor mode 1350 (as explainedabove).

The pump system can determine and store amplitudes and/or offsets atother target pressures, such as at or around −67 mmHg (−9.0 kPa). Insome embodiments, the pump system can determine and store amplitudesand/or offsets for pressures corresponding to at or around ambientpressure and at or around pressure thresholds, such as the low pressurethreshold and the high pressure threshold. For example, the pump systemcan determine and store amplitudes and offsets for pressurescorresponding to ambient pressure, a negative pressure less than thehigh pressure threshold and a negative pressure greater than the lowpressure threshold. In some embodiments, the pump system can determineand store amplitudes and/or offsets for pressures outside of the normaloperating range during a maintenance mode, such as maintenance mode1350.

The pump system can determine and store an offset and/or amplitude atfewer or greater target pressures as desired. For example, in someembodiments, the pump system can determine and store an offset and/oramplitude at 5 target pressures. Moreover, the pump system can determineand store an offset and/or amplitude at different pressures from thoselisted as may be desired. For example, storing an offset and/oramplitude at a greater number of pressures can result in a moreefficient pump system.

In some embodiments, the pump system can also determine and store anamplitude and/or offset at a negative pressure value greater than thetypical operating range for the pump system. For example, the pumpsystem can determine and store an amplitude and/or offset at or around−218 mmHg (−29 kPa). The stored amplitude and/or offset at or around−218 mmHg can be equal to or less than the stored amplitude and/oroffset at the upper operating negative pressure range for the pumpsystem, such as −94 mmHg. In storing such an amplitude and/or offset ata higher negative pressure, the flow through the pump system at highernegative pressures can be reduced and thereby reduce the likelihood ofdamage to components of the pump system.

In any embodiments disclosed herein, the pump system can determine orcalculate one or more parameters of the drive signal based on operatingconditions of the pump, such as the current and/or desired negativepressure. For example, the pump system can calculate an offset and/oramplitude for the drive signal. In some embodiments, the pump system cancalculate the offset and/or amplitude for the drive signal based atleast on part on the stored parameters in the pump system. This canbeneficially reduce the total number of parameters stored on the pumpsystem thereby reducing the amount of memory needed in the pump system.Moreover, as will be discussed in further detail below, this can alsoreduce the time needed to calibrate the pump. In some embodiments, thepump system can interpolate between two or more of the storedparameters. For example, the pump system can interpolate, such aslinearly interpolate, between two or more of the stored parameters.Other types of interpolation can also be used, such as polynomial andspline interpolation. The pump system can use other algorithms forcalculating one or more parameters for the drive signal. A combinationof such techniques can also be used.

FIG. 67 illustrates a calibration process or method 1600 for obtainingone or more parameters of the drive signal according to someembodiments. In some embodiments, the one or more parameters stored inthe pump system can be based on performance of the pump system duringsuch calibration. The calibration can be performed during manufacturingor production after the pump assembly of the pump system has beenpartially or fully assembled. Calibration can be particularly beneficialfor pump assemblies with low manufacturing or assembly tolerances, suchas small-scale pumps including small-scale voice coil pumps which aredescribed herein. For example, minor variances during manufacture andinstallation can potentially significantly alter the optimal parametersbetween a first pump assembly and a second pump assembly. Accordingly,calibration can significantly enhance the efficiency of such pumpsystems. The calibration method 1600 can be used to calibrate any of thepump embodiments disclosed herein.

In some embodiments, calibration of the pump system can be performed bya calibration system, which can implement the process 1600. Thecalibration system (not shown) can include components such as, but notlimited to, a pneumatic chamber for applying pressure, one or moresensors for measuring movement of one or more components of the pumpsystem, memory, controller, input and output interfaces, and the like.Calibration can beneficially be used to ensure that a source of negativepressure within the pump system is operating at or near its maximumefficiency for one or more target pressures. Moreover, calibration canalso be beneficial for ensuring that components of the source ofnegative pressure do not contact mechanical stops, thereby preventingwear and tear, malfunction and reducing noise and vibration. Withrespect to some sources of negative pressure, such as diaphragm pumpshaving a piston assembly for moving a diaphragm, the force applied tothe diaphragm can result in different levels of movement based on thepressure within the pump. Accordingly, the amount of force applied atdifferent pressures should be varied to reduce or eliminate thelikelihood that components of the pump, such as the piston assembly,will contact mechanical stops which can cause noise, vibration, andharshness.

As shown in the illustrated embodiment, when the calibration is firstperformed on the pump system, the calibration system can perform aninitialization step 1602. During the initialization step 1602, thecalibration system can reset a calibration attempts counter (e.g.,setting the counter to a value such as 0, 1, or any other value asdesired). During the initialization step 1602, the calibration systemcan generate an initial set of parameters for a drive signal to apply toa pump assembly of the pump system being calibrated. The initial set ofparameters, such as an initial offset, initial amplitude and/or initialfrequency, can be based on a preset values for the pressure beingcalibrated. In some embodiments, the initial set of parameters can alsobe based on the performance of the pump system for previously calibratedpressures. In some embodiments, the initial set of parameters can alsobe set by the user. This can advantageously reduce the amount of timeneeded to calibrate the pump system. In some embodiments, thecalibration system can test the polarity of the pump system and adjustthe parameters accordingly. This can beneficially account for anyreversals in polarity during the assembly process.

In some embodiments, during the initialization step 1602, thecalibration system can measure one or more positions of components ofthe pump including, but not limited to, a piston assembly of the pumpassembly. For example, the calibration system can measure one or morepositions of a support such as support member 650, a shaft such as shaft700, a coil such as coil 600, and/or a diaphragm such as diaphragm 550.In some embodiments, such as those involving a pump system having asingle translational degree of freedom including, but not limited to,pump systems utilizing a voice coil actuator, the calibration system canmeasure the position of the one or more components when the pumpassembly is inactive (“rest”), the position of the one or morecomponents when at a first end for those components (“top dead center”),and/or the position of the one or more components is at the opposite endfor those components (‘bottom dead center”). In some embodiments, thecalibration system can set the coordinate system such that a zeroposition is the average point between the top dead center and bottomdead center with the top dead center being a positive value and thebottom dead center being a negative value.

With reference next to step 1604, the calibration system can determinewhether the system should attempt to perform the calibration. In someembodiments, the calibration system can be configured such that thesystem will perform only a certain number of calibration attempts. Thiscan advantageously prevent or reduce the likelihood that the calibrationsystem will expend significant time and resources in attempting tocalibrate the pump system. In some embodiments, the number ofcalibration attempts can be a preset number. In some embodiments, thenumber of calibration attempts can be set by the user. In someembodiments, the number of calibration attempts can be variable and canbe based on performance of the pump system for previously calibratedpressures.

As shown in the illustrated embodiment in FIG. 67, the calibrationsystem can determine whether the counter is greater than a set value ofcalibration attempts. If the counter is greater than to the set value ofcalibration attempts, the calibration system can determine that thecalibration has failed as shown in step 1606 and the process 1600terminates. In some embodiments, the calibration can provide a user withan indication that the calibration has failed such as via a visualand/or audio indicator. If the counter is less than or equal to the setvalue of calibration attempts, the system can transition to step 1608.

With reference to step 1608, in some embodiments, the calibration systemcan actuate one or more components of the pump system using the setparameters. For example, the calibration system can actuate a coil of avoice coil actuator with a set frequency, offset, and/or amplitude. Insome embodiments, the calibration system can continue to actuate one ormore components of the pump system for one or more periods or a setduration of time to help ensure that the pump system has reached arelatively steady state.

With reference to step 1610, the calibration system can measure movementof one or more components of the pump system while the pump system isbeing actuated in accordance with step 1608. For example, thecalibration system can measure one or more positions of a support suchas support member 650, a shaft such as shaft 700, a coil such as coil600, and/or a diaphragm such as diaphragm 550. In some embodiments, suchas those involving a pump system having a single translational degree offreedom including, but not limited to, pump systems utilizing a voicecoil actuator, the calibration system can measure a linear position ofthe one or more components. In some embodiments, the calibration systemcan begin to measure movement of the pump system after a set number ofperiods or a set duration of time. This can beneficially help to ensurethat the pump system has reached a relatively steady state prior totaking measurements of the device.

During step 1610, the calibration system can calculate one or moredimensions based on the measured movement of the one or more componentsof the pump system. For example, the calibration system can calculate atravel and/or average position of one or more components. In someembodiments, the travel can be based on a linear distance between a highposition (i.e., the highest positive position value measured) and a lowposition (i.e., the highest negative position value measured) of the oneor more components. An exemplary graph 1700 of travel over multipleiterations is illustrated in FIG. 68 with the x-axis being the iterationand the y-axis being the calculated travel. The high position and thelow position can be an average position values based on two or moreperiods of calibration or can be the maximum and minimum position valuesmeasured. An exemplary graph 1750 of average position over multipleiterations is illustrated in FIG. 69 with the x-axis being the iterationand the y-axis being the calculated average position. In someembodiments, the calibration system can calculate additional oralternative parameters based on the measure movement or some othercharacteristic of the pump system, such as expelled fluid volume, flowrate, etc.

During step 1612, the calibration system can determine whether themeasured movement of the one or more components of the pump system meetsa target value within a desired tolerance. For example, the calibrationsystem can determine whether the calculated travel and/or the averageposition of the one or more components of the pump system meets a targetvalue for travel within a tolerance of 10%. The target value and/ortolerance can be a preset value based on the specific pressure beingcalibrated. In some embodiments, the tolerance can be betweenapproximately 0.1% to approximately 20%, between approximately 0.5% toapproximately 10%, between approximately 1% to approximately 5%,approximately 2%, any sub-range of the following ranges, and/or anyother tolerance as desired. In some embodiments, the target value and/orthe desired tolerance can be set by the user. In some embodiments, thetolerances can be the same for the travel and average positionparameters. In some embodiments, the tolerances can be different.

In some embodiments, such as those involving a pump system having asingle translational degree of freedom including, but not limited to,pump systems utilizing a voice coil actuator, the target value and/ortolerances can be chosen such that components of the pump assembly, suchas a piston assembly, do not contact the mechanical stops or at leasthas a reduced likelihood of contacting the mechanical stops.

If the calibration system determines that the measure movement of theone or more components of the pump system do not meet the target valuewithin a desired tolerance, the calibration system can transition tostep 1614 and adjust the set parameters, such as the offset and/oramplitude. In some embodiments, the adjustments to the set parameterscan be based at least in part on the previous measurements andcalculations. The calibration system can then transition back to step1604. In some embodiments, the calibration system can increase thecounter by one.

If the calibration system determines that the measure movement of theone or more components of the pump system meet the target value within adesired tolerance, the calibration system can transition to step 1616and determine whether a convergence condition has been met. In someembodiments, the convergence condition can include meeting the targetvalue within a desired tolerance for a set number of iterations. In someembodiments, the convergence condition can include a condition that thecalculated travel satisfies a target travel within tolerances for one ormore iterations as shown, for example, in region 1702 of FIG. 68. Insome embodiments, the convergence condition can include a condition thatthe calculated average position meeting a target average position withintolerances for one or more iterations as shown, for example, in region1752 of FIG. 69. In some embodiments, the convergence condition caninclude that two or more conditions be satisfied substantiallysimultaneously or simultaneously. If the convergence condition has beenmet, the calibration system can transition to step 1618 and store theset parameters in the pump system, such as in memory. In step 1618, theprocess 1600 terminates successfully. If the convergence condition hasnot been met, the calibration system can transition to step 1604. Insome embodiments, the calibration system can increase the counter byone.

In some embodiments, the process 1600 can be repeated for each targetpressure in the set of target pressures (such as three target pressuresas described above). For each target pressure in the set, parameters canbe determined and stored. When the pump system is activated by the userto provide negative pressure wound therapy, stored parameters can beutilized in order to determine how to drive the negative pressuresource. For example, when an offset sinusoidal signal is used fordriving the actuator, such as the voice coil motor, stored parametersare used to determine the offset and amplitude of the sinusoidal signalin order to achieve a target pressure. When a particular target pressuredoes not coincide with any of the target pressures in set for whichparameters have been determined (through calibration) and stored, thepump system can determine parameters for achieving the particular targetpressure by interpolation, such as linear interpolation. In someembodiments, the stored parameters can be combined in any suitablelinear or non-linear manner in order to calculate parameters forachieving the particular target pressure.

Filter Blocked Determination

FIG. 70 illustrates a process or method 1800 for determining whether afilter blockage is present in a pump system according to someembodiments. The process 1800 can be implemented by the controller of apump system, such as controllers 1114, 1202, and the process 1800 can beimplemented as part of executing the state diagram 1300. The method 1800can be used to determine the existence of a filter blockage for any ofthe pump embodiments disclosed herein. In some embodiments, it can beadvantageous to alert the user if a filter blockage has occurred so thatthe user can take remedial actions to relieve the blockage. For example,in embodiments where the filter is contained within a wound dressing, afilter blockage may be triggered if the wound dressing is at or nearingcapacity for storing wound exudate and requires replacement. In someembodiments, the rate of execution of the method 1800 can be based on(or be the same as) the pressure sampling rate for the pump system. Inother embodiments, the method 1800 can be performed at a rate differentfrom the pressure sampling rate for the pump system.

Transition of the pump system to an active state, such as the IPD state1314 or the MPD state 1354 is illustrated in FIG. 70 by the active state1802. Upon transitioning to the active state 1802, the pump system canactivate a source of negative pressure, such as a pump assembly as shownin step 1804.

In some embodiments, while the pump assembly is in the active state1802, the pump system can intermittently and/or continuously monitor thepressure within the pump system or some portion thereof, such as a fluidflow path between a source of negative pressure and a wound dressing.Based on the measured pressure within the pump system or some portionthereof, the pump system can calculate a rate of pressure change basedon a difference between two or more pressure values and the amount oftime between the measurements. As shown in the illustrated embodiment,the process 1800 can transition from step 1804 to step 1806, where theprocess 1800 can determine whether the calculated rate of pressurechange or drop exceeds a threshold value. For example, the thresholdvalue can be approximately −50 mmHg/second (6,750 Pals). The thresholdvalue can be between approximately −20 mmHg/second and approximately−200 mmHg/second, between approximately −40 mmHg/second andapproximately −100 mmHg/second, between approximately −50 mmHg/secondand approximately −75 mmHg/second, approximately −70 mmHg/second, anyvalue or subrange within these ranges, or any other threshold asdesired.

The threshold value can be calculated based on the volume of the fluidflow pathway between the source of negative pressure and the wounddressing, such as the manifold (e.g., manifold 300 of pump system 100)and conduit (e.g., conduits 904, 906), the volume of the wound dressing,and the flow rate of the source of negative pressure. For a given flowrate of the source of negative pressure, the rate of pressure changewithin the fluid flow path between the source of negative pressure andthe wound dressing would vary depending on the amount of exudate orother incompressible fluids within the wound dressing. As the amount ofexudate or other incompressible fluids within the wound dressingincreases, the rate of pressure change within the fluid flow path wouldincrease as a result of the reduced volume of compressible fluids withinthe wound dressing. Accordingly, it is possible to estimate theremaining capacity of the wound dressing based on the calculated rate ofpressure change. As such, it is possible to estimate the remainingcapacity without use of other sensors, such as a dressing sensor, flowsensor, and the like. The threshold value can be set at or around therate of pressure change exhibited by a wound dressing at or nearcapacity.

Should the process 1800 determine that the rate of pressure changesatisfies (e.g., exceeds) the threshold rate, the process 1800 cantransition from step 1806 to step 1808 and increase the value of afilter block detection counter. In some embodiments, the process 1800can increase the value of the counter by 1 although any other value canbe used. Moreover, in some embodiments, the increase in value of thecounter can be based on other factors, such as the calculated rate ofpressure drop.

In some circumstances, it is possible that the calculated rate ofpressure change or drop can greatly exceed the threshold rate ofpressure change. For example, in circumstances where the conduit iskinked or blocked proximate the manifold, the rate of pressure changecan be significant. It can be advantageous to differentiate between sucha transient blockage condition and a more permanent filter blockedcondition. As such, in some embodiments, when the process 1800determines that a calculated rate of pressure change exceeds a maximumrate of pressure change, the process 1800 may not increase the counterand/or may provide a different indication to the user. In someembodiments, the maximum rate can be equal to or greater thanapproximately 110% of the threshold rate, equal to or greater thanapproximately 120% of the threshold rate, equal to or greater thanapproximately 130% of the threshold rate, equal to or greater thanapproximately 140% of the threshold rate, equal to or greater thanapproximately 150% of the threshold rate, or any other percentage of thethreshold rate.

When the process 1800 determines that the rate of pressure change doesnot satisfy (e.g., does not exceed) the threshold rate, the process 1800can advance to step 1810 and, in some embodiments, decrease the value ofthe counter. In some embodiments, the process 1800 can decrease thevalue of the counter by 1 although any other value can be used. Forexample, the process 1800 can reset the counter to its initial value,such as 0, 1, or any other suitable value. In some embodiments, thedecrease in value of the counter can be based on other factors, such asthe calculated rate of pressure drop. In some embodiments, the process1800 can ensure that the value of the counter does not decrease belowthe initial value, such as 0.

During step 1812, the process 1800 can determine whether the counter hasreached a set value that represents a threshold number of times that therate of pressure change has satisfied the threshold rate. The set valuecan be a preset value from the factory, can be a variable value based onother parameters of the pump, or can be set by the user. In someembodiments, the set value can beneficially be set to a value higherthan 1. A value higher than 1 can be advantageous as it can reduce thelikelihood of a false positive which may be caused by a factor otherthan a filter blockage, such as an outlier pressure reading, a kink inthe conduit located in the fluid flow path between the pump system andthe wound dressing, or other similar factors. If the process 1800determines that the counter satisfies the set value (e.g., is equal tothe set value), the process 1800 can transition to a filter blockedstate 1814. In some embodiments, in state 1814, the pump system canperform the operations discussed in connection with state 1318 discussedin connection with FIG. 63.

If the process 1800 determines that the counter does not satisfy the setvalue (e.g., is smaller than the set value), the process 1800 system cantransition to step 1816 where it determines whether the pressure withinthe pump system or some portion thereof is at or near a low pressurethreshold. If not, the process can continue to maintain the pump in anactive state and transition to step 1804. If the process 1800 determinesthat the pressure within the pump system or some portion thereof is ator near a low pressure threshold, the process 1800 can transition to themonitor state 1818, which can be the same as or similar to the monitorstate 1352 discussed in connection with FIG. 63. Accordingly, in someembodiments, the pump system can deactivate the pump and monitor thepressure within the pump system or some portion thereof. As is explainedabove, the process 1800 can transition to step 1820 where it determinesif the pressure within the pump system or some portion thereof is at ornear a high pressure threshold. In case that the pressure has reachedthe high pressure threshold, the process 1800 can then proceed to step1804 and perform operations explained above.

An exemplary graph 1900 of pressure versus time during the IPD state1910, monitor state 1920, and MPD state 1930 is illustrated in FIG. 71.As shown in the illustrated embodiment, during the IPD state 1910, thepump system can sample the pressure at two or more points in timerepresented on the graph as points 1912, 1914 corresponding to pressuresP1 at time t1 and P2 at time t2 respectively. The rate of change ofpressure between these two points can be calculated according to:(P2−P1)/(t2−t1).

In some circumstances, the abrupt pressure drops from point 1916 topoint 1914 represents a transient blockage, such as a kinked conduit inthe fluid flow path. As is explained above, the process 1800 can detectthis condition by determining that the rate of change of pressuregreatly exceeds the threshold, and can refrain from updating thecounter.

FIG. 72 illustrates another process or method 2000 for determiningwhether a filter blockage is present in a pump system according to someembodiments. The process 2000 can be implemented by the controller of apump system, such as controllers 1114, 1202, and the process 2000 can beimplemented as part of executing the state diagram 1300. The method 2000can be used to determine the existence of a filter blockage for any ofthe pump embodiments disclosed herein. In some embodiments, it can beadvantageous to alert the user if a filter blockage has occurred so thatthe user can take remedial actions to relieve the blockage. For example,in embodiments where the filter is contained within a wound dressing, afilter blockage may be triggered if the wound dressing is at or nearingcapacity and requires replacement. In some embodiments, the rate ofexecution of the method 2000 can be based on (or be the same as) thepressure sampling rate for the pump system. In other embodiments, themethod 2000 can be performed at a rate different from the pressuresampling rate for the pump system.

As shown in the illustrated embodiment, during step 2010 the pump systemcan determine whether a measured negative pressure within the pumpsystem or some portion thereof pressure is greater than or equal to ahigh pressure threshold and/or less than or equal to a low pressurethreshold. If so, the pump system can store the measured pressure (P1)and the time (t1), such as in memory, as shown in step 2015. The pumpsystem can then transition to step 2020.

During step 2020, the pump system can determine whether the measurednegative pressure is greater than a high pressure threshold. If not, thepump system can transition to step 2025 and delete the stored pressure(P1) and time (t1) and transition back to step 2010. If the pump systemdetermines that the measured negative pressure is greater than the highpressure threshold, the pump system can transition to step 2030. Duringstep 2030, the pump system can determine whether the measured negativepressure is greater than a low pressure threshold. If not, the pumpsystem can transition back to step 2020. If the pump system determinesthat the measured negative pressure is greater than the low pressurethreshold, the pump system can store the measured pressure (P2) and time(t2) that this occurs as shown in step 2035. The pump system can thentransition to step 2040.

During step 2040, the pump system can determine a rate of pressurechange or drop between the two stored pressures. The pump system candetermine whether the calculated rate of pressure change or drop exceedsa threshold value. For example, the threshold value can be approximately−50 mmHg/second (6,750 Pals). The threshold value can be betweenapproximately −20 mmHg/second and approximately −200 mmHg/second,between approximately −40 mmHg/second and approximately −100mmHg/second, between approximately −50 mmHg/second and approximately −75mmHg/second, approximately −70 mmHg/second, any value or subrange withinthese ranges, or any other threshold as desired.

When the process 2000 determines that the rate of pressure change doesnot satisfy (e.g., does not exceed) the threshold rate, the process 2000can advance to step 2045 and, in some embodiments, decrease the value ofa filter block detection counter. For example, if the process 2000determines that the counter is greater than 0, the pump system cantransition to step 2050 and decrease the value of the counter. In someembodiments, the pump system can decrease the value of the counter by 1although any other value can be used. For example, the process 2000 canreset the counter to its initial value, such as 0, 1, or any othersuitable value. In some embodiments, the decrease in value of thecounter can be based on other factors, such as the calculated rate ofpressure drop. As shown in the illustrated embodiment, the process 2000can ensure that the value of the counter does not decrease below theinitial value, such as 0, as a result of step 2045. Accordingly, ifduring step 2045 the process 2000 determines that the counter is notgreater than 0, the process 2000 can transition to step 2025.

Should the process 2000 determine that the rate of pressure change,shown as (P2−P1)/(t2−t1), satisfies (e.g., exceeds) the threshold rate,the process 2000 can transition from step 2040 to step 2055 and increasethe value of the counter. In some embodiments, the process 2000 canincrease the value of the counter by 1 although any other value can beused. Moreover, in some embodiments, the increase in value of thecounter can be based on other factors, such as the calculated rate ofpressure drop.

As noted above in connection with process 1800 described in connectionwith FIG. 70, in some circumstances, it is possible that the calculatedrate of pressure change or drop can greatly exceed the threshold rate ofpressure change. As such, in some embodiments, when the process 2000determines that a calculated rate of pressure change exceeds a maximumrate of pressure change, the process 2000 may not increase the counterand/or may provide a different indication to the user. In someembodiments, the maximum rate can be equal to or greater thanapproximately 110% of the threshold rate, equal to or greater thanapproximately 120% of the threshold rate, equal to or greater thanapproximately 130% of the threshold rate, equal to or greater thanapproximately 140% of the threshold rate, equal to or greater thanapproximately 150% of the threshold rate, or any other percentage of thethreshold rate.

During step 2060, the process 2000 can determine whether the counter hasreached a set value that represents a threshold number of times that therate of pressure change has satisfied the threshold rate. The set valuecan be a preset value from the factory, can be a variable value based onother parameters of the pump, or can be set by the user. In someembodiments, the set value can beneficially be set to a value higherthan 1. If the process 2000 determines that the counter satisfies theset value (e.g., is greater than or equal to the set value), the process2000 can transition to a filter blocked state 2065. In some embodiments,in state 2065, the pump system can perform the operations discussed inconnection with state 1318 discussed in connection with FIG. 63. If theprocess 2000 determines that the counter does not satisfy the set value(e.g., is not greater than or equal to the set value), the process 2000can transition to step 2025.

With respect to the method 2000, the rate of pressure change iscalculated based on two measured negative pressures, the first of whichis measured when the negative pressure is between a high pressurethreshold and a low pressure threshold and the second of which ismeasured when the negative pressure is greater than the low pressurethreshold. In some instances, the duration of time between the first andsecond measured negative pressures can be greater than, if notsignificantly greater than, a sampling rate of the pump system.Accordingly, there can be a lower likelihood of a false positive whichmay be caused by a factor other than a filter blockage, such as anoutlier pressure reading, a kink in the fluid flow path between the pumpsystem and the wound dressing, or other similar factors which may causea transient pressure change of significant magnitude.

Other processes or methods for determining whether a filter blockage ispresent in a pump system are also appreciated, which can be implementedby the controller of a pump system, such as controllers 1114 or 1202,and which can be implemented as part of executing the state diagram1300. For example, in some embodiments, the presence of a blockage canbe determined based on the level of activity of the pump, such asmeasured duty cycle. In some embodiments, the processes or methods cancompare the level of activity of the pump, such as measured duty cycle,to a blockage threshold, which can be adjusted based on whether the pumpis operating without or with a canister. In some embodiments, thedetection of whether a canister is present can be performedautomatically, for example, by the controllers 1114 or 1202. Automaticdetection can be performed using one or more of the followingapproaches: characteristics of pressure distribution in a fluid flowpath (including characteristics of decaying pressure, settling pressure,etc.), sensor indicating attachment and/or presence of the canister,RFID detection, actuating a switch indicating attachment and/or presenceof the canister, and the like.

In any embodiments disclosed herein, the drive signal for the source ofnegative pressure can be attenuated upon start up to slowly ramp up or“soft start” the source of negative pressure. For example, in someembodiments, parameters such as the offset and/or amplitude of the drivesignal can be reduced when the source of negative pressure is firstactivated after having previously been inactive for some period of time.In soft starting the source of negative pressure, the forces applied toone or more components of the source of negative pressure can bereduced.

As noted above, at a lower negative pressure, such as 0 mmHg, a loweramplitude for the drive signal may be desirable since the piston willexhibit a greater degree of movement for a given amplitude at the lowervacuum condition whereas at a higher negative pressure, such as −70mmHg, a higher amplitude may be desirable since the piston will exhibita lesser degree of movement for a given amplitude at the higher vacuumcondition. Accordingly, should the source of negative pressure besubject to a drive signal with amplitude and offset calculated for thetarget pressure of, for instance −70 mmHg, when the pressure within thediaphragm pump is at 0 mmHg, there is a potential that the source ofnegative pressure can be over driven, thereby causing a reduction inefficiency. Further, over driving the source of negative pressure cancause contact between one or more components within the source ofnegative pressure. For example, for a source of negative pressure whichutilizes a voice coil actuator, over driving the voice coil actuator cancause components such as a support, shaft, or piston to contactmechanical stops which can cause noise, vibration, and harshness.

Soft starting the source of negative pressure can be done any time thesource of negative pressure is being activated after being inactive. Insome embodiments, soft starting can be performed only after the sourceof negative pressure has been inactive for a set period of time. The setperiod can be a preset value, a variable parameter based on operatingconditions of the pump system, and/or input by the user.

As noted above, in some embodiments, the pump system can calculate theoffset and/or amplitude for the drive signal based at least on part onthe stored parameters in the pump system. In some embodiments, during asoft start, the pump system can activate the source of negative pressurewith a drive signal corresponding to a lower negative pressure than themeasured negative pressure, such as approximately −15 mmHg (−2 kPa) whenthe measured negative pressure is −70 mmHg. In some embodiments, thepump system can activate the source of negative pressure with otherdrive signals, such as a drive signal between approximately 0 mmHg andapproximately −100 mmHg, between approximately −5 mmHg and approximately−75 mmHg, between approximately −10 mmHg and approximately −50 mmHg,between approximately −15 mmHg and approximately −25 mmHg, any value orsubrange within these ranges, or any other pressure as desired. Thepressure can be a preset value, a variable parameter based on operatingconditions of the pump system, and/or input by the user.

In some embodiments, the pump system can actuate the source of negativepressure with a soft start drive signal for a set duration of time. Theset duration of time can be sufficient to ensure that the source ofnegative pressure is at or near the measured pressure in the pump systemor some portion thereof, such that application of a drive signal at themeasured pressure would be less likely to over drive the source ofnegative pressure. For example, the duration can be approximately 100ms. In some embodiments, the duration can be between approximately 10 msand approximately 1000 ms, between approximately 50 ms and approximately500 ms, between approximately 75 ms and approximately 250 ms,approximately 100 ms, any value or subrange within these ranges, and anyother duration as desired. The duration can be a preset value, avariable parameter based on operating conditions of the pump system,and/or input by the user.

Other Embodiments

The following described embodiments are other embodiments contemplatedby this disclosure:

-   -   1. An apparatus for use in negative pressure wound therapy,        comprising:        -   a pump assembly, comprising:            -   a pump housing;            -   a magnet positioned within the pump housing;            -   an electrically conductive coil positioned within the                pump housing; and            -   a diaphragm, wherein the coil is directly or indirectly                coupled with the diaphragm and is configured to move at                least a portion of the diaphragm to pump a fluid through                the pump assembly; and        -   a dampener positioned within the pump assembly configured to            reduce sound generated by the pump assembly during operation            of the pump assembly.    -   2. The apparatus of Claim 1, wherein the dampener comprises a        porous material configured to allow fluid to flow through the        dampener.    -   3. The apparatus of Claim 2, wherein the porous material is        urethane foam.    -   4. The apparatus of Claim 1, wherein the pump housing comprises        a chamber, and wherein the dampener is positioned within the        chamber.    -   5. The apparatus of Claim 4, wherein the chamber is integrally        formed with the pump housing.    -   6. The apparatus of Claims 4, further comprising a diffuser        positioned within the chamber, the diffuser configured to        facilitate expansion of fluid as it enters the chamber.    -   7. The apparatus of Claim 4 or 5, wherein the pump housing        further comprises an exhaust channel configured to communicate        fluid flow out of the pump assembly, and wherein the chamber is        in communication with the exhaust channel.    -   8. The apparatus of Claim 7, wherein the exhaust channel        comprises an opening along the channel configured to redirect a        portion of a fluid flow from the exhaust channel back into an        internal volume of the housing, wherein said redirection is        configured to reduce sound generated by the pump assembly during        operation of the pump assembly.    -   9. The apparatus of Claim 8, wherein the portion of the fluid        flow from the exhaust channel comprises an entirety of a fluid        flow from the exhaust channel.    -   10. The apparatus of any previous claim, further comprising a        manifold positioned such that the manifold is between the pump        assembly and a wound dressing when the apparatus is in use.    -   11. The apparatus of Claim 10, further comprising a diffuser        positioned within the manifold.    -   12. The apparatus of Claim 10, further comprising a second        dampener within the manifold.    -   13. The apparatus of Claim 12, wherein the second dampener        comprises a porous material configured to allow fluid to flow        through the dampener.    -   14. The apparatus of Claim 13, wherein the porous material of        the second dampener is urethane foam.    -   15. The apparatus of any previous claim, further comprising a        control board.    -   16. The apparatus of Claim 15, further comprising an electrical        conduit for connecting the control board to the electrically        conductive coil.    -   17. The apparatus of any previous claim, wherein the pump        assembly further comprises:        -   an upper pole;        -   a lower pole spaced apart from the upper pole; and        -   one or more valves configured to control a flow of fluid            through the pump assembly;        -   wherein at least a portion of the coil is positioned between            the upper and the lower pole, and        -   wherein the magnet is positioned between at least a portion            of the upper pole and the lower pole.    -   18. The apparatus of Claim 17, wherein a portion of each of the        one or more valves comprises a rib extending away from a surface        of the valve, the rib being configured to compress or deform to        increase a seal with a corresponding sealing surface.    -   19. The apparatus of Claims 17, wherein the pump assembly        further comprises a pump chamber body configured to receive the        one or more valves in one or more corresponding valve recesses.    -   20. The apparatus of Claim 19, wherein a sealant is positioned        between the pump chamber body and the housing.    -   21. The apparatus of Claim 19, wherein the pump assembly further        comprises one or more valve chambers formed in part by a union        between a portion of an outer surface of the pump chamber body        and a portion of an inner surface of the housing.    -   22. The apparatus of Claim 19, wherein the one or more valve        recesses further comprise one or more indexing features        configured to receive one or more corresponding alignment        features of the one or more valves to inhibit improper valve        installation into the pump chamber body.    -   23. The apparatus of any previous claim, further comprising a        wound dressing configured to sealingly surround a wound.    -   24. The apparatus of any previous claim, comprising a spring        member, wherein:        -   a periphery of the spring member is supported within the            pump assembly so as to be in a fixed position relative to            the diaphragm; and        -   a middle portion of the spring member is configured to            deflect relative to the periphery of the spring member when            a middle portion of the diaphragm axially deflects.    -   25. The apparatus of any previous claim, further comprising an        illumination source disposed within the housing, wherein part of        the housing is transparent or translucent such that light        emitted from the illumination source passes through the housing.    -   26. The apparatus of any previous claim, wherein the dampener is        a filter configured to filter fluid as it flows through the        dampener.    -   27. The apparatus of Claim 1, further comprising a dampener        positioned on an exterior surface of the pump housing.    -   28. A pump apparatus, comprising:        -   a housing having a first section and a second section; and        -   an illumination source disposed within the housing adjacent            the first section;        -   wherein the illumination source is configured to illuminate            the first section,        -   wherein the first section is one of transparent and            translucent, and        -   wherein the first section is thinner than the second section            as measured perpendicularly from inside to outside the            housing.    -   29. The pump apparatus of Claim 28, wherein the second section        is opaque.    -   30. The pump apparatus of Claims 28, wherein the illumination        source comprises light emitting diodes (LED).    -   31. The pump apparatus of Claim 28, wherein the first section        comprises an icon.    -   32. The pump apparatus of Claim 28, further comprising a pump        assembly disposed within the housing configured for negative        pressure wound therapy.    -   33. The pump apparatus of Claim 32, wherein the first section        comprises four icons.    -   34. The pump apparatus of Claim 33, wherein one of the four        icons comprises an indicator configured to illuminate when the        pump assembly is operating properly, a second of the four icons        comprises an indicator configured to illuminate when there is a        leak, a third of the four icons comprises an indicator        configured to illuminate when a dressing connected to the wound        apparatus is full, and a fourth of the four icons comprises an        indicator indicating that a battery level is low.    -   35. The pump apparatus according Claim 28, further comprising a        baffle configured to control an illumination of the first        section by absorbing light.    -   36. The pump apparatus of Claim 35, wherein the baffle is        configured to inhibit an illumination of one part of the first        section from illuminating another part of the first section,        wherein illumination comprises light passing through a        transparent or translucent portion of the of the first section.    -   37. The pump apparatus of Claim 35 or 36, wherein the baffle is        directly or indirectly connected to or integrally formed with at        least one of the first and second sections.    -   38. A pump apparatus, comprising:        -   a pump casing with one or more transparent portions            configured to allow a laser to pass therethrough; and        -   a component housing configured to be laser welded to the            pump casing, the component housing comprising one or more            laser absorbing portions configured to be melted by the            laser.    -   39. The pump apparatus of Claim 38, wherein the one or more        laser absorbing portions are darker than the one or more        transparent portions.    -   40. The pump apparatus of Claim 38 or 39, wherein the one or        more laser absorbing portions comprises at least one of        nontransparent material and laser absorbing material.    -   41. The pump apparatus of Claim 40, wherein the at least one of        nontransparent material and laser absorbing material is        positioned on the surface of the component housing or extends        through a thickness of the component housing.    -   42. The pump apparatus of Claim 40 or 41, wherein the at least        one of nontransparent material and laser absorbing material        comprises 5% to 100% black pigment.    -   43. The pump apparatus according to any of Claims 38-42, wherein        at least a portion of the pump casing is transparent and wherein        at least a portion of the component housing is at least one of        nontransparent and laser absorbent.    -   44. The pump apparatus according to any of Claims 38-43, wherein        the one or more laser absorbing portions of the component        housing represent a weld contour to which the laser is        configured to be applied.    -   45. The pump apparatus according to any of Claims 38-44, wherein        the component housing houses at least one of one or more valves,        a diaphragm, a magnet, and an electrically conductive coil.    -   46. The pump apparatus according to any of Claims 38-45, wherein        a portion of the one or more transparent portions of the pump        casing comprises part of an intake channel and an outtake        channel on the exterior of the pump casing, the intake and        outtake channels having sloped surfaces to prevent sudden laser        diffraction during laser welding.    -   47. A pump apparatus, comprising:        -   a transparent pump component configured to allow a laser to            pass through during laser welding; and        -   a housing configured to be laser welded to the transparent            pump component, the housing comprising one or more laser            absorbing portions configured to be melted by the laser.    -   48. The pump apparatus of Claim 47, wherein the housing        comprises one or more weld surfaces comprising the one or more        laser absorbing portions.    -   49. The pump apparatus of Claim 48, wherein the one or more weld        surfaces comprises at least six circumferential weld surfaces.    -   50. The pump apparatus of Claim 49, wherein the at least six        circumferential weld surfaces are equally spaced apart.    -   51. The pump apparatus according to any of Claims 47-50, the        housing further comprising one or more vertical flanges, wherein        each vertical flange comprises two weld surfaces and one stop,        the stop configured to control a collapse of the transparent        pump component into the housing during welding.    -   52. The pump apparatus of Claim 51, wherein the two weld        surfaces of each of the one or more vertical flanges comprises        the one or more laser absorbing portions.    -   53. The pump apparatus according to any of Claims 47-52, wherein        the transparent pump component comprises a bushing.    -   54. The pump apparatus according to any of Claims 47-52, wherein        the housing comprises a pump chamber body.    -   55. An apparatus for use in negative pressure wound therapy,        comprising:        -   a pump system configured for negative pressure wound            therapy, comprising:            -   an outer housing;            -   a pump assembly positioned within the outer housing, the                pump assembly comprising a pump housing that receives a                plurality of pump components therein; and            -   a connector for connecting a tube or conduit to the pump                system to deliver negative pressure from the pump                assembly to a wound.    -   56. The apparatus of Claim 55, further comprising an intake        manifold within the outer housing providing fluid communication        between the connector and the pump assembly.    -   57. The apparatus of Claim 55, further comprising a circuit        board positioned within the outer housing configured to control        the pump assembly.    -   58. The apparatus of Claim 55, further comprising a wound        dressing configured to connect to the tube or conduit.    -   59. The apparatus of Claim 55, wherein the pump housing        comprises a chamber formed integrally with the pump housing,        wherein the chamber receives a dampening component.    -   60. The apparatus of Claim 55, wherein the pump housing        comprises an exhaust channel, the exhaust channel configured to        redirect a fluid flow from the exhaust channel into an internal        volume of the pump housing to reduce sound generated by the pump        assembly during operation.    -   61. The apparatus of Claim 55, wherein the pump assembly        comprises a noise reduction system.    -   62. The apparatus of Claim 55, wherein the pump components        received within the pump housing comprise a magnet, an        electrically conductive coil, a diaphragm, and a dampener.    -   63. The apparatus of Claim 62, wherein the pump components        received within the pump housing comprise a spring configured to        interact with the diaphragm.    -   64. The apparatus of Claim 62, wherein the pump components        received within the pump housing comprise an upper pole, a lower        pole, and a valve, wherein the magnet and a portion of the        electrically conductive coil are disposed between the upper and        lower poles.    -   65. The apparatus of Claim 64, wherein the valve comprises a rib        configured to better seal the rib against a sealing surface.    -   66. The apparatus of Claim 55, wherein the outer housing        comprises a display comprising a plurality of indicators.    -   67. The apparatus of Claim 55, wherein the outer housing        comprises relatively thinner material, transparent material, or        translucent material overlying an illumination component on the        inside of the outer housing.    -   68. The apparatus of Claim 67, further comprising baffles        attached to or formed integrally with interior surfaces of the        outer housing to prevent illumination of one indicator from        bleeding into and onto another indicator.    -   69. The apparatus of Claim 55, further comprising one or more        user input features on an outside surface of the outer housing.    -   70. The apparatus of Claim 55, wherein one or more of the pump        housing and the pump components are transparent to facilitate        laser welding during assembly of the pump system.    -   71. A negative pressure pump system comprising:        -   a pump assembly comprising:            -   an actuator; and            -   a diaphragm; and        -   a controller configured to control operation of the pump            system, the controller further configured to:            -   calculate at least one of an amplitude and an offset for                a drive signal based at least in part on previously                calculated parameters and a negative pressure setting;            -   generate the drive signal with the at least one                calculated amplitude and offset; and            -   apply the drive signal to the pump system, thereby                causing delivery of negative pressure wound therapy.    -   72. The negative pressure pump system of embodiment 71, wherein        the previously calculated parameters comprise a plurality of        calibrated amplitudes at a plurality of negative pressure        settings.    -   73. The negative pressure pump system of embodiment 71 or 72,        wherein the previously calculated parameters comprise a        plurality of calibrated offsets at a plurality of negative        pressure settings.    -   74. The negative pressure pump system according to any of        embodiments 71-73, wherein the controller is further configured        to calculate both the amplitude and the offset for the drive        signal.    -   75. The negative pressure pump system according to any of        embodiments 71-74, wherein the controller is further configured        to interpolate between at least two previously calculated        amplitudes or offsets.    -   76. The negative pressure pump system of embodiment 75, wherein        the controller is further configured to linearly interpolate        between at least two previously calculated amplitudes or        offsets.    -   77. The negative pressure pump system according to any of        embodiments 71-76, wherein the previously calculated parameters        comprises at least 3 parameters.    -   78. The negative pressure pump system according to any of        embodiments 71-77, wherein the previously calculated parameters        are dependent on one or more properties of the pump system.    -   79. The negative pressure pump system according to any of        embodiments 71-78, wherein the actuator comprises a voice coil        actuator, the voice coil actuator being connected to the        diaphragm.    -   80. The negative pressure pump system according to any of        embodiments 71-79, wherein the pump assembly further comprises a        spring configured to affect a resonant frequency of the pump        assembly.    -   81. The negative pressure pump system according to any of        embodiments 71-80, wherein the controller is further configured        to apply a start up signal when the pump system has been        activated after a period of inactivity, the start up signal        comprising at least one of an amplitude and an offset different        from at least one of the amplitude and the offset of the drive        signal.    -   82. The negative pressure pump system according to embodiment        81, wherein the controller is further configured to:        -   calculate at least one of an amplitude and an offset for the            start up signal based at least in part on previously            calculated parameters and a soft start negative pressure            setting that is less than the negative pressure setting; and        -   apply the start up signal to the pump system.    -   83. The negative pressure pump system according to embodiment        82, wherein the controller is further configured to apply the        start up signal to the pump system over a start up time period        until the soft start negative pressure setting is reached under        a wound dressing configured to be placed over a wound, and        subsequently apply the drive signal to the pump system.    -   84. The negative pressure pump system according to embodiment        83, wherein the controller is configured to apply the drive        signal to the pump system until the negative pressure setting is        reached under the wound dressing.    -   85. The negative pressure pump system according to embodiment 83        or 84, wherein the start up time period is approximately 100        milliseconds.    -   86. The negative pressure pump system according to embodiment 83        or 84, wherein the start up time period is between approximately        10 milliseconds and approximately 1000 milliseconds.    -   87. The negative pressure pump system according to embodiment 83        or 84, wherein the start up time period is between approximately        50 milliseconds and approximately 500 milliseconds.    -   88. The negative pressure pump system according to embodiment 83        or 84, wherein the start up time period is between approximately        75 milliseconds and approximately 250 milliseconds.    -   89. A calibration system for calibrating a pump system        configured for negative pressure wound therapy, the calibration        system comprising:        -   a sensor; and        -   a controller configured to control operation of the            calibration system, the controller further configured to:            -   cause generation of a drive signal;            -   cause actuation of the pump system with the drive                signal;            -   measure movement of a component of the pump system with                the sensor;            -   calculate a first dimension based on the measured                movement of the component; and            -   determine whether a first convergence condition has been                satisfied by determining that the first dimension is                within a first tolerance of a first target value.    -   90. The calibration system of embodiment 89, wherein the        controller is further configured to:    -   calculate a second dimension based on the measured movement of        the component; and    -   determine whether a second convergence condition has been        satisfied by determining that the second dimension is within a        second tolerance of a second target value.    -   91. The calibration system of embodiment 90, wherein the        controller is further configured to determine that the first and        second convergence conditions are satisfied substantially        simultaneously.    -   92. The calibration system according to any of embodiments        89-91, wherein, upon determining that at least one of the first        or second convergence conditions is met, the controller is        further configured to store a set of parameters associated with        the drive signal in a memory of the pump system.    -   93. The calibration system according to any of embodiments        89-92, wherein, upon determining that at least one of the first        or second convergence conditions is not satisfied, the        controller is further configured to:        -   cause adjustment of one or more parameters of the drive            signal based at least in part on the measured movement of            the component;        -   cause generation of an adjusted drive signal;        -   cause actuation of the pump system with the adjusted drive            signal;        -   measure the movement of the component of the pump assembly            with the sensor; and        -   determine whether the convergence condition has been            satisfied.    -   94. The calibration system according to any of embodiments        89-93, wherein the controller is further configured to cause        selection of an amplitude of the drive signal for generation of        at least one of the drive signal and the adjusted drive signal.    -   95. The calibration system according to any of embodiments        89-94, wherein the controller is further configured to cause        selection of an offset of the drive signal for generation of at        least one of the drive signal and the adjusted drive signal.    -   96. The calibration system according to any of embodiments        90-95, wherein at least one of the first and second dimensions        comprises a travel of the component.    -   97. The calibration system according to any of embodiments        90-96, wherein at least one of the first and second dimensions        comprises an average position of the component.    -   98. The calibration system according to any of embodiments        90-97, wherein the component comprises a piston connected to a        diaphragm.    -   99. A method for controlling a pump system configured for        negative pressure wound therapy, the method comprising:        -   calculating at least one of an amplitude and an offset for a            drive signal based at least in part on previously calculated            parameters and a negative pressure setting;        -   generating the drive signal with the at least one calculated            amplitude and offset; and        -   applying the drive signal to the pump system, and thereby            causing delivery of negative pressure wound therapy;        -   wherein the method is performed under control of a            controller of the pump system.    -   100. The method of embodiment 99, wherein the previously        calculated parameters comprise a plurality of calibrated        amplitudes at a plurality of negative pressure settings.    -   101. The method of embodiment 99 or 100, wherein the previously        calculated parameters comprise a plurality of calibrated offsets        at a plurality of negative pressure settings.    -   102. The method of according to any of embodiments 99-101,        wherein calculating the at least one of the amplitude and the        offset for a drive signal comprises calculating both the        amplitude and the offset for the drive signal.    -   103. The method according to any of embodiments 99-102, wherein        calculating the at least one of the amplitude and the offset for        the drive signal further comprises interpolating between at        least two previously calculated amplitudes or offsets.    -   104. The method of embodiment 103, wherein the interpolation is        a linear interpolation.    -   105. The method according to any of embodiments 99-104, wherein        the previously calculated parameters comprises at least 3        parameters.    -   106. The method according to any of embodiments 99-105, wherein        the previously calculated parameters are dependent on one or        more properties of the pump system.    -   107. The method according to any of embodiments 99-106, wherein        the pump system comprises a voice coil actuator connected to a        diaphragm.    -   108. The method according to any of embodiments 99-107, wherein        the pump system further comprises a spring configured to affect        a resonant frequency of the pump system.    -   109. The method according to any of embodiments 99-108, further        comprising applying a start up signal when the pump system has        been activated after a period of inactivity, the start up signal        comprising at least one of an amplitude and an offset different        from at least one of the amplitude and the offset of the drive        signal.    -   110. The method according to embodiment 108, further comprising:        -   calculating at least one of the amplitude and the offset for            the start up signal based at least in part on previously            calculated parameters and a soft start negative pressure            setting that is less than the negative pressure setting; and        -   applying the start up signal to the pump system.    -   111. The method according to embodiment 110, wherein applying        the start up signal comprises applying the start up signal to        the pump system over a start up time period until the soft start        negative pressure setting is reached under a wound dressing        configured to be placed over a wound, and subsequently applying        the drive signal to the pump system.    -   112. The method according to embodiment 111, wherein the drive        signal is applied to the pump system until the negative pressure        setting is reached under the wound dressing.    -   113. The method according to embodiment 111 or 112, wherein the        start up time period is approximately 100 milliseconds.    -   114. The method according to embodiment 111 or 112, wherein the        start up time period is between approximately 10 milliseconds        and approximately 1000 milliseconds.    -   115. The method according to embodiment 111 or 112, wherein the        start up time period is between approximately 50 milliseconds        and approximately 500 milliseconds.    -   116. The method according to embodiment 111 or 112, wherein the        start up time period is between approximately 75 milliseconds        and approximately 250 milliseconds.    -   117. A method for calibrating a pump system configured for        negative pressure wound therapy, the method comprising:        -   causing generation of a drive signal;        -   causing actuation of the pump system with the drive signal;        -   measuring movement of a component of the pump system;        -   calculating a first dimension based on the measured movement            of the component; and        -   determining whether a first convergence condition has been            satisfied by determining that the first dimension is within            a first tolerance of a first target value, wherein the            method is performed under control of a controller of a            calibration system.    -   118. The method of embodiment 117, further comprising:        -   calculating a second dimension based on the measured            movement of the component; and        -   determining whether a second convergence condition is            satisfied by determining that the second dimension is within            a second tolerance of a second target value.    -   119. The method of embodiment 118, further comprising        determining that the first and second convergence conditions are        satisfied substantially simultaneously.    -   120. The method according to any of embodiments 117-119, further        comprising in response to determining that at least one of the        first or second convergence conditions is met, storing in a        memory of the pump system a set of parameters associated with        the drive signal.    -   121. The method according to any of embodiments 117-120, wherein        the method further comprises in response to determining that at        least one of the first or second convergence conditions is not        satisfied:        -   causing adjustment of one or more parameters of the drive            signal based at least in part on the measured movement of            the component;        -   causing generation of an adjusted drive signal;        -   causing actuation of the pump system with the adjusted drive            signal;        -   measuring the movement of the component of the pump            assembly; and        -   determining whether the convergence condition has been            satisfied.    -   122. The method according to any of embodiments 117-121, wherein        causing generation of the drive signal or the adjusted drive        signal comprises selecting an amplitude of the drive signal.    -   123. The method according to any of embodiments 117-122, wherein        causing generation of the drive signal or the adjusted drive        signal comprises selecting an offset of the drive signal.    -   124. The method according to any of embodiments 118-123, wherein        at least one of the first and second dimensions comprises a        travel of the component.    -   125. The method according to any of embodiments 118-124, wherein        at least one of the first and second dimensions comprises an        average position of the component.    -   126. The method according to any of embodiments 118-125, wherein        the component comprises a piston connected to a diaphragm.    -   127. A pump system configured for negative pressure wound        therapy, the pump system comprising:        -   a pump assembly configured to provide a negative pressure,            via a flow path, to a wound dressing configured to be            positioned over a wound, the flow path configured to            fluidically connect the pump system to the wound dressing;        -   a sensor configured to measure a pressure in the flow path;            and        -   a controller configured to control operation of the pump            system, the controller further configured to:        -   measure a first pressure value in the flow path at a first            time;        -   measure a second pressure value in the flow path at a second            time;        -   calculate a first rate of pressure change using the first            and second pressure values; and        -   provide an indication that the wound dressing is full in            response to determining that the calculated first rate of            pressure change satisfies a threshold rate of change.    -   128. The pump system of Claim 127, wherein the controller is        further configured to:        -   measure a third pressure value in the flow path at a third            time;        -   measure a fourth pressure value within the flow path at a            fourth time;        -   calculate a second rate of pressure change using the third            and fourth pressure values; and        -   provide the indication that the wound dressing is full in            response to determining that the calculated first and second            rates of pressure change satisfy the threshold rate of            change.    -   129. The pump system of Claim 127 or 128, wherein the pressure        in the fluid flow path is between a maximum pressure and a        minimum pressure.    -   130. The pump system of any of Claims 127 to 129, wherein the        controller is further configured to determine whether the second        pressure value is less than a minimum pressure.    -   131. The pump system of any of Claims 127 to 130, wherein the        controller is further configured to provide an indication that        the wound dressing is full in response to determining that the        calculated first rate of pressure change equals or exceeds the        threshold rate of change.    -   132. The pump system of any of Claims 127 to 131, wherein the        threshold rate of change is approximately −50 mmHg/second.    -   133. The pump system of any of Claims 127 to 131, wherein the        threshold rate of change is approximately −70 mmHg/second.    -   134. The pump system of any of Claims 127 to 131, wherein the        threshold rate of change is between approximately −20        mmHg/second and approximately −200 mmHg/second.    -   135. The pump system of any of Claims 127 to 131, wherein the        threshold rate of change is between approximately −40        mmHg/second and approximately −100 mmHg/second.    -   136. The pump system of any of Claims 127 to 131, wherein the        threshold rate of change is between approximately −50        mmHg/second and approximately −75 mmHg/second.    -   137. The pump system of any of Claims 127 to 136, wherein the        controller is further configured to provide an indication of a        transient blockage condition in response to determining that the        calculated first rate of pressure change satisfies a maximum        rate of change.    -   138. The pump system of any of Claims 127 to 137, wherein the        controller is further configured to provide an indication of a        transient blockage condition in response to determining that the        calculated first and second rates of pressure change satisfy a        maximum rate of change.    -   139. The pump system of Claim 137 or 138, wherein the transient        blockage condition comprises at least one of a kink in the flow        path and an occlusion in the flow path.    -   140. The pump system of any of Claims 137 to 138, wherein the        maximum rate of change comprises about 110%, about 120%, about        130%, about 140%, or about 150% of the threshold rate.    -   141. The pump system of any of Claims 137 to 138, wherein the        maximum rate of change comprises between about 105% and about        155% of the threshold rate of change.    -   142. The pump system of any of Claims 137 to 141, wherein the        controller is further configured to provide an indication of a        transient blockage condition in response to determining that the        calculated first rate of pressure change equals or exceeds the        maximum rate of change.    -   143. The pump system of any of Claims 127 to 142 wherein the        controller is further configured to sample a pressure within the        fluid flow path during one or more time intervals.    -   144. The pump system of Claim 143, wherein the controller is        further configured to sample the pressure at least twice during        each of the one or more time intervals.    -   145. The pump system of Claim 143 or 144, wherein the controller        is further configured to average the pressure samples during        each of the one or more time intervals.    -   146. A method for controlling a pump system configured for        negative pressure wound therapy, the method comprising:        -   causing provision of negative pressure, via a flow path, to            a wound dressing configured to be positioned over a wound,            the flow path configured to fluidically connect the pump            system to the wound dressing;        -   measuring a first pressure value in the flow path at a first            time;        -   measuring a second pressure value in the flow path at a            second time;        -   calculating a first rate of pressure change using the first            and second pressure values; and        -   in response to determining that the calculated first rate of            pressure change satisfies a threshold rate of change,            providing an indication that the wound dressing is full,        -   wherein the method is performed under control of a            controller of the pump system.    -   147. The method of Claim 146, further comprising:        -   measuring a third pressure value in the flow path at a third            time;        -   measuring a fourth pressure value within the flow path at a            fourth time;        -   calculating a second rate of pressure change using the third            and fourth pressure values; and        -   providing the indication that the wound dressing is full in            response to determining that the calculated first and second            rates of pressure change satisfy the threshold rate of            change.    -   148. The method of Claim 146 or 147, wherein the pressure in the        fluid flow path is between a maximum pressure and a minimum        pressure.    -   149. The method of any of Claims 146 to 148, further comprising        determining whether the second pressure value is less than a        minimum pressure.    -   150. The method of any of Claims 146 to 149, wherein satisfying        the threshold rate of change comprises equaling or exceeding the        threshold rate of change.    -   151. The method of any of Claims 146 to 150, wherein the        threshold rate of change is approximately −50 mmHg/second.    -   152. The method of any of Claims 146 to 150, wherein the        threshold rate of change is approximately −70 mmHg/second.    -   153. The method of any of Claims 146 to 150, wherein the        threshold rate of change is between approximately −20        mmHg/second and approximately −200 mmHg/second.    -   154. The method of any of Claims 146 to 150, wherein the        threshold rate of change is between approximately −40        mmHg/second and approximately −100 mmHg/second.    -   155. The method of any of Claims 146 to 150, wherein the        threshold rate of change is between approximately −50        mmHg/second and approximately −75 mmHg/second.    -   156. The method of any of Claims 146 to 155, further comprising        providing an indication of a transient blockage condition in        response to determining that the calculated first rate of        pressure change satisfies a maximum rate of change.    -   157. The method of any of Claims 146 to 156, further comprising        providing an indication of a transient blockage condition in        response to determining that the calculated first and second        rates of pressure change satisfy a maximum rate of change.    -   158. The method of Claim 156 or 157, wherein the transient        blockage condition comprises at least one of a kink in the flow        path and an occlusion in the flow path.    -   159. The method of any of Claims 156 to 158, wherein the maximum        rate of change comprises about 110%, about 120%, about 130%,        about 140%, or about 150% of the threshold rate of change.    -   160. The method of any of Claims 156 to 158, wherein the maximum        rate of change comprises between about 105% and about 155% of        the threshold rate of change.    -   161. The method of Claim any of Claims 156 to 160, wherein        satisfying the maximum rate of change comprises equaling or        exceeding the maximum rate of change.    -   162. The method of any of Claims 146 to 161, wherein measuring        the pressure values within the flow path comprises sampling a        pressure within the fluid flow path during one or more time        intervals.    -   163. The method of Claim 162, further comprising sampling the        pressure at least twice during each of the one or more time        intervals.    -   164. The method of Claim 162 or 163, further comprising        averaging the pressure samples during each of the one or more        time intervals.    -   165. A pump system configured for negative pressure wound        therapy, the pump system comprising:        -   a pump assembly comprising:            -   an actuator; and            -   a diaphragm; and        -   a controller configured to control operation of the pump            system, the controller further configured to:            -   apply a drive signal to the pump assembly, the drive                signal alternating between a positive amplitude and a                negative amplitude and the drive signal having an                offset; and            -   sample a pressure within a fluid flow path configured to                connect the pump assembly to a wound dressing configured                to be placed over a wound during one or more time                intervals, wherein each of the one or more time                intervals occurs when the drive signal is approximately                at an amplitude equal to one or more sampling                amplitudes.    -   166. The pump system of Claim 165, wherein the sampling        amplitude comprises a local maxima of the amplitude.    -   167. The pump system of Claim 165 or 166, wherein the sampling        amplitude comprises a local minima of the amplitude.    -   168. The pump system according to any of Claims 165-167, wherein        the sampling amplitude comprises a zero crossing of the        amplitude.    -   169. The pump system according to any of Claims 165-168, wherein        the sampling amplitude comprises an offset crossing of the        amplitude.    -   170. The pump system according to any of Claims 165-169, wherein        the controller is further configured to sample the pressure at        least twice during each of the one or more time intervals.    -   171. The pump system of Claim 170, wherein the controller is        further configured to average the pressure samples during each        time interval.    -   172. The pump system of any of Claims 165-171, wherein the        controller is further configured to adjust at least one        parameter of the drive signal based on the pressure samples.    -   173. A method for controlling a pump system configured for        negative pressure wound therapy, the method comprising:        -   applying a drive signal to a pump assembly of the pump            system, the drive signal alternating between a positive            amplitude and a negative amplitude and the drive signal            having an offset; and        -   sampling a pressure within a fluid flow path configured to            connect the pump system to a wound dressing configured to be            placed over a wound during one or more time intervals,            wherein each of the one or more time intervals occurs when            the drive signal is approximately at an amplitude equal to            one or more sampling amplitudes,        -   wherein the method is performed under control of a            controller of the pump system.    -   174. The method of Claim 173, wherein the sampling amplitude        comprises a local maxima of the amplitude.    -   175. The method of Claim 173 or 174, wherein the sampling        amplitude comprises a local minima of the amplitude.    -   176. The method according to any of Claims 173-175, wherein the        sampling amplitude comprises a zero crossing of the amplitude.    -   177. The method according to any of Claims 173-176, wherein the        sampling amplitude comprises an offset crossing of the        amplitude.    -   178. The method according to any of Claims 173-177, further        comprising sampling the pressure at least twice during each of        the one or more time intervals.    -   179. The method of Claim 178, further comprising averaging the        pressure samples during each time interval.    -   180. The method of any of Claims 173-179, further comprising        adjusting at least one parameter of the drive signal based on        the pressure samples.        Any apparatus and method described in this application can        include any combination of the preceding features described in        this and other paragraphs, among other features and combinations        described herein, including features and combinations described        in subsequent paragraphs, and including any features and        combinations described in any application incorporated by        reference herein.

Any value of a threshold, limit, duration, etc. provided herein is notintended to be absolute and, thereby, can be approximate. In addition,any threshold, limit, duration, etc. provided herein can be fixed orvaried either automatically or by a user. Furthermore, as is used hereinrelative terminology such as exceeds, greater than, less than, etc. inrelation to a reference value is intended to also encompass being equalto the reference value. For example, exceeding a reference value that ispositive can encompass being equal to or greater than the referencevalue. In addition, as is used herein relative terminology such asexceeds, greater than, less than, etc. in relation to a reference valueis intended to also encompass an inverse of the disclosed relationship,such as below, less than, greater than, etc. in relations to thereference value.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel methods and systems describedherein may be embodied in a variety of other forms. Furthermore, variousomissions, substitutions and changes in the systems and methodsdescribed herein may be made without departing from the spirit of thedisclosure. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the disclosure. Accordingly, the scope of the presentdisclosure is defined only by reference to the claims presented hereinor as presented in the future.

Features, materials, characteristics, or groups described in conjunctionwith a particular aspect, embodiment, or example are to be understood tobe applicable to any other aspect, embodiment or example described inthis section or elsewhere in this specification unless incompatibletherewith. All of the features disclosed in this specification(including any accompanying claims, abstract and drawings), and/or allof the steps of any method or process so disclosed, may be combined inany combination, except combinations where at least some of suchfeatures and/or steps are mutually exclusive. The protection is notrestricted to the details of any foregoing embodiments. The protectionextends to any novel one, or any novel combination, of the featuresdisclosed in this specification (including any accompanying claims,abstract and drawings), or to any novel one, or any novel combination,of the steps of any method or process so disclosed.

Furthermore, certain features that are described in this disclosure inthe context of separate implementations can also be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation can also beimplemented in multiple implementations separately or in any suitablesubcombination. Moreover, although features may be described above asacting in certain combinations, one or more features from a claimedcombination can, in some cases, be excised from the combination, and thecombination may be claimed as a subcombination or variation of asubcombination.

Moreover, while operations may be depicted in the drawings or describedin the specification in a particular order, such operations need not beperformed in the particular order shown or in sequential order, or thatall operations be performed, to achieve desirable results. Otheroperations that are not depicted or described can be incorporated in theexample methods and processes. For example, one or more additionaloperations can be performed before, after, simultaneously, or betweenany of the described operations. Further, the operations may berearranged or reordered in other implementations. Those skilled in theart will appreciate that in some embodiments, the actual steps taken inthe processes illustrated and/or disclosed may differ from those shownin the figures. Depending on the embodiment, certain of the stepsdescribed above may be removed, others may be added. Various componentsillustrated in the figures may be implemented as software and/orfirmware on a processor, controller, ASIC, FPGA, and/or dedicatedhardware. Hardware components, such as processors, ASICs, FPGAs, and thelike, can include logic circuitry. Furthermore, the features andattributes of the specific embodiments disclosed above may be combinedin different ways to form additional embodiments, all of which fallwithin the scope of the present disclosure. Also, the separation ofvarious system components in the implementations described above shouldnot be understood as requiring such separation in all implementations,and it should be understood that the described components and systemscan generally be integrated together in a single product or packagedinto multiple products.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures are described herein. Not necessarily all such advantages maybe achieved in accordance with any particular embodiment. Thus, forexample, those skilled in the art will recognize that the disclosure maybe embodied or carried out in a manner that achieves one advantage or agroup of advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements, and/or steps areincluded or are to be performed in any particular embodiment.

Conjunctive language such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to convey that an item, term, etc. may beeither X, Y, or Z. Thus, such conjunctive language is not generallyintended to imply that certain embodiments require the presence of atleast one of X, at least one of Y, and at least one of Z.

Language of degree used herein, such as the terms “approximately,”“about,” “generally,” and “substantially” as used herein represent avalue, amount, or characteristic close to the stated value, amount, orcharacteristic that still performs a desired function or achieves adesired result. For example, the terms “approximately”, “about”,“generally,” and “substantially” may refer to an amount that is withinless than 10% of, within less than 5% of, within less than 1% of, withinless than 0.1% of, and within less than 0.01% of the stated amount. Asanother example, in certain embodiments, the terms “generally parallel”and “substantially parallel” refer to a value, amount, or characteristicthat departs from exactly parallel by less than or equal to 15 degrees,10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree.

The scope of the present disclosure is not intended to be limited by thespecific disclosures of preferred embodiments in this section orelsewhere in this specification, and may be defined by claims aspresented in this section or elsewhere in this specification or aspresented in the future. The language of the claims is to be interpretedbroadly based on the language employed in the claims and not limited tothe examples described in the present specification or during theprosecution of the application, which examples are to be construed asnon-exclusive.

1. A pump system configured for negative pressure wound therapy, thepump system comprising: a pump assembly comprising: an actuator; and adiaphragm; and a controller configured to control operation of the pumpsystem, the controller further configured to: apply a drive signal tothe pump assembly, the drive signal alternating between a positiveamplitude and a negative amplitude and the drive signal having anoffset; and sample a pressure within a fluid flow path configured toconnect the pump assembly to a wound dressing configured to be placedover a wound during one or more time intervals, wherein each of the oneor more time intervals occurs when the drive signal is approximately atan amplitude equal to one or more sampling amplitudes.
 2. The pumpsystem of claim 1, wherein the sampling amplitude comprises a localmaxima of the amplitude.
 3. The pump system of claim 1, wherein thesampling amplitude comprises a local minima of the amplitude.
 4. Thepump system of claim 1, wherein the sampling amplitude comprises a zerocrossing of the amplitude.
 5. The pump system of claim 1, wherein thesampling amplitude comprises an offset crossing of the amplitude.
 6. Thepump system of claim 1, wherein the controller is further configured tosample the pressure at least twice during each of the one or more timeintervals.
 7. The pump system of claim 6, wherein the controller isfurther configured to average the pressure samples during each timeinterval.
 8. The pump system of claim 1, wherein the controller isfurther configured to adjust at least one parameter of the drive signalbased on the pressure samples.
 9. A method for controlling a pump systemconfigured for negative pressure wound therapy, the method comprising:applying a drive signal to a pump assembly of the pump system, the drivesignal alternating between a positive amplitude and a negative amplitudeand the drive signal having an offset; and sampling a pressure within afluid flow path configured to connect the pump system to a wounddressing configured to be placed over a wound during one or more timeintervals, wherein each of the one or more time intervals occurs whenthe drive signal is approximately at an amplitude equal to one or moresampling amplitudes, wherein the method is performed under control of acontroller of the pump system.
 10. The method of claim 9, wherein thesampling amplitude comprises a local maxima of the amplitude.
 11. Themethod of claim 9, wherein the sampling amplitude comprises a localminima of the amplitude.
 12. The method of claim 9, wherein the samplingamplitude comprises a zero crossing of the amplitude.
 13. The method ofclaim 9, wherein the sampling amplitude comprises an offset crossing ofthe amplitude.
 14. The method of claim 9, further comprising samplingthe pressure at least twice during each of the one or more timeintervals.
 15. The method of claim 14, further comprising averaging thepressure samples during each time interval.
 16. The method of claim 9,further comprising adjusting at least one parameter of the drive signalbased on the pressure samples.
 17. (canceled)